Postdoc Appreciation Week Spotlight Update: Sangwoo (Steven) Park

September 21-25, 2026, is National Postdoc Appreciation Week. Since 2009, the National Postdoctoral Association (NPA) has sponsored this annual celebration to recognize the significant contributions that postdoctoral scholars make to research and scientific discovery. Check out the NPA website to view the virtual and in-person events being held this week. 

This week, BPS will be highlighting postdoc members on the blog. Today, we're hearing an update from Sangwoo (Steven) Park, Harvard Medical School and Massachusetts General Hospital, originally spotlighted in 2025. Click here to read his first spotlight.

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Background & Inspiration 

1. Can you tell us a little about your background and what brought you to your current postdoc position? 

I started out in physics during my undergraduate years, and during my PhD under Professor Matthew Paszek’s guidance, I became very interested in biophysics and glycobiology. My work focused on the sugar layer on the cell membrane, called the glycocalyx, and how its physical properties affect interactions with immune cells. Toward the end of my PhD, I realized that the glycocalyx can physically block cell-cell interactions, including interactions between cancer cells and immune-cell therapies. That naturally led me to the immunotherapy field and to Professor Marcela Maus’s lab, where I started developing ways to help CAR-T cells overcome this barrier in solid tumors.

Since my last spotlight, I have been able to make this idea much more concrete. One direction I became especially interested in was physically reducing the glycocalyx using enzymes. Many enzymes that can do this come from bacteria, so I started looking for human enzymes that could remodel the cancer-cell surface. We have now combined one of these enzymes with CAR-T cells to improve their activity against solid tumors, and we are currently preparing the manuscript. It has been exciting to see an idea that started from a basic biophysics question become something much closer to an engineered therapeutic strategy.

2. What inspired you to pursue research in your field? 

This has not really changed since my first spotlight. During my military service as a firefighter and EMT in South Korea, I once transported a patient with stage 4 lung cancer. At that moment, all I could do was provide oxygen, check his blood pressure, and get him to the hospital. That feeling of not being able to do more stayed with me for a long time. Eventually, I decided that I wanted to help patients in a different way by becoming a scientist. Since my background was in physics, cancer biophysics and eventually cancer immunotherapy became a natural path for me. The specific science I work on has changed over time, but that original motivation is still the same.

Daily Work & Routine 

3. What does a typical day look like for you as a postdoc? 

My routine has changed quite a bit. Now that I am on the job market, I try to concentrate my experimental work as much as possible while I am in the lab and do more of my writing (grants, manuscripts, applications) at home. I am also spending more time mentoring students and technicians, so I have realized that I actually have less uninterrupted time for experiments than I used to. Because of that, I try to be much more efficient with my time and plan experiments carefully. My days now include a mixture of experiments, meetings, mentoring, data analysis, and writing. One thing that has not changed is that I still find writing grants and manuscripts late at night surprisingly productive. For some reason, once everything becomes quiet, I can focus much better.

4. Do you have a favorite part of your daily routine—or a task you look forward to most? 

Last time, I said that I liked doing cell culture when I needed a break because it was simple and helped me clear my head. Unfortunately, I now have less time even for that! Instead, I recently started waking up early and trying to run at least 5 km every morning. It has become one of my favorite parts of the day. At the beginning of the run, I am mostly trying to wake myself up. Somewhere in the middle, I usually start thinking about experiments, grants, or whatever problem I am working on. By the end, I am tired enough that I stop thinking about anything, which is probably the best part. It has been a surprisingly good way to start the day.

5. What’s one part of your day that people might find surprising or unexpected? 

I try to make sure that I have enough time for my family, even when work gets busy. One slightly unusual habit I have is that when my wife travels or has a business trip, I tend to pack as much work as possible into those days. I will stay late, write more, and try to finish things that have been sitting on my list. It actually works well for me because I can focus intensely while she is away, and then when she comes back, I feel much better about stepping away from work and spending time together. 

Research & Impact 

6. Can you briefly describe your research project and why it matters? 

My research focuses on the glycocalyx, which is a sugar-rich layer covering the cell surface. Depending on the cell, it can range from nanometers to even micrometers in thickness. Even very small changes in this layer can affect whether an immune cell can physically get close enough to recognize and kill a cancer cell. My current work asks whether we can manipulate this layer to make cell therapies work better in solid tumors. In particular, we are developing CAR-T cells that can locally remodel the tumor glycocalyx using human enzymes. The idea is fairly simple. Instead of only engineering the CAR-T cell to recognize a tumor antigen, we can also engineer it to change the biophysical environment around the tumor cell, making that antigen easier to reach. I think this matters because many solid tumors are not just difficult to recognize. They are physically difficult for immune cells to engage. If we can address both problems at the same time, it may give us another way to improve cell therapy for solid cancers.

7. What’s the most exciting discovery or moment you’ve had during your postdoc so far? 

Scientifically, it has been very exciting to see our glycocalyx ideas move from basic observations into actual CAR-T cell engineering strategies. But some of the most meaningful moments of my postdoc have also come from the people I have met along the way. Through several rising-star and early-career programs, I have had the chance to meet many amazing fellowship awardees, including Damon Runyon Fellowship, NIH K award and so on, at a similar career stage. There are so many incredibly smart people, and it is easy to feel stressed when everyone is going through the job market at the same time. At the same time, I have really enjoyed being part of that community. We talk not only about science, but also about applications, interviews, career decisions, and life in general. Sharing information and going through the same uncertain stage together has made the process much more enjoyable. I am very grateful for that.

Personal Touch 

8. How do you balance life in the lab with life outside of it? 

I think my answer has changed a little. As I started mentoring more students and technicians, my schedule became filled with more meetings, writing, and responsibilities outside of my own experiments. Because of that, the boundary between work and home has probably become even less clear. I honestly do not think about ‘work-life balance’ as a strict separation very often. I like being busy, even if it sometimes makes me anxious, and I genuinely enjoy a lot of what I do. For me, the important thing is more about priorities. Family comes first. If there is something important for my family, I will make time for it. And when my wife is traveling, I am also perfectly happy using that opportunity to get a certain amount of work done. So I am not sure I have found balance, but I think I have become better at knowing what should take priority at different times.

9. What hobbies or activities help you recharge after work? 

Recently, running has become the biggest one for me. I have not been running for very long, and I do not have any big goal like running a race yet. Right now, I just enjoy trying to run a little every morning. There is something I really like about having that time to myself. Sometimes I think about research, sometimes about life, and sometimes about absolutely nothing. Even though it is a small part of my day, it has become surprisingly important for keeping me energized. I still enjoy traveling, walking around with my wife, watching movies, and meeting friends as well. Golf is still something I keep saying I will practice more seriously someday.

10. Any fun lab quirks? 

Last time, I said I was a coffee addict. Unfortunately, I think I may have overdone it. Recently, coffee has started bothering my stomach, probably because I was drinking too much of it. So I am now trying to drink more tea and limit myself to one cup of coffee a day. I am not very happy about this change. I still really like coffee, so watching everyone else get another cup while I try to convince myself that tea is just as good has been one of the more difficult adjustments of my postdoc.

Advice & Future 

11. What advice would you give to someone just starting a postdoc? 

My answer to this has not changed very much. Papers and funding are obviously important, and everyone starting a postdoc already knows that. What I think gets overlooked is how important the people around you are. Your lab mates are often the people who understand your situation better than anyone else. Depending on the lab, everyone’s experience will be different, but having colleagues you can talk to makes this difficult stage much easier. I would now extend that advice beyond your own lab. I have also found it extremely valuable to become friends with people at a similar career stage whom I meet through conferences, fellowships, and scientific programs. I have learned things from them that I would never have figured out by myself about science, grants, the job market, interviews, and even life decisions. I am always grateful for those relationships.

12. Where do you see yourself heading next in your career? 

I am currently on the faculty job market, so I hope that the next step will be becoming an independent investigator and starting my own lab. I still have a lot to learn, but I feel much closer to that goal than I did when I answered this question the first time. I want to build a research program that brings together glycobiology, biophysics, and cell engineering to develop better therapies for cancer. More broadly, I hope I can keep pursuing questions that I find meaningful, contribute something useful to patients and society, and eventually create an environment where the next generation of scientists can develop their own ideas as well. That is still the goal, and I am working hard to get there.