Celebrating our Butterfly Research Leader - Sebastiaan van Heesch

1) Sometimes we wonder if a research idea is worth pursuing and if we should develop it further. How are you sure to continue in a given topic of research?

I think you can address this from a short-term and a long-term view. In the short term, within your PhD, if something looks exciting, it is always worth exploring to some extent. You should figure out if you are looking at a technical artifact or a true new biological phenomenon. If you can exclude the first, I would say go for it. All exciting new findings tend to be high-risk, high-reward. In the long term, this is about how you build your career. Looking back at mine, I changed topics several times, but there is a common thread, which is mostly driven by my interest in new systems, new diseases, and new technologies. I was always given a lot of freedom by my supervisors (PhD and post-doc) to explore on my own; I was never handed a project. This was quite tough in the beginning, but it worked out. My advice is to go where your findings lead you, and if you don’t know what you want to work on in five years, that’s okay. Five years from now, a lot will have changed.

2) From an outsider’s point of view, it seems that your career was very smooth and that you, compared to others, became a PI quite quickly. How would you describe your path to becoming a PI? Did you deviate from the academic path during your career?

During my master’s, I really wanted to do an internship in industry, but I didn’t feel inspired by it. It wasn’t the right fit for me, so I decided to go for a PhD. The work we do in my group is derived from a side project from my PhD research. At the time, my supervisor had another passion, but I was very excited about this topic. I teamed up with different post-docs and another PhD student, and we eventually published the project, which contributed to the start of the field. I think this translates into good advice for current PhD students: if you find the right match with more experienced PhDs and post-docs, it can be very beneficial for you, and it can help push your ideas further.

Then I decided to go for a post-doc in Berlin. One of the main reasons was that I really wanted to go abroad, and I hadn’t had that opportunity during my studies. My post-doc was five and a half years, which was longer than intended. When I finished it, I considered several options, including an offer to head an R&D department in a start-up company in Amsterdam. Although both options involved state-of-the-art development of novel cancer therapies, I eventually opted for a PI position at the Máxima center because as a young father myself I felt a strong urge to contribute to curing cancer in children. The research PI position also gave me the freedom to explore my own ideas and figure out how these can be translated to the clinic. Plus, it felt too soon to transition into industry. Maybe at some point, I will consider starting a company as a spin-off from the work we are doing in the lab.

3) Since we touched upon supervision and inspiring people, what do you consider your supervision style to be? How do you manage to stay approachable and present?

I try to be approachable and present, but it’s very difficult sometimes, as life gets very busy. I try to make time for everyone, but it also has to be fair and equally distributed. I used to have one-on-one meetings with everyone, at least once every two weeks, but since the group has grown quite a lot, that is no longer manageable. My team and I are now actively figuring out how to structure our interaction moments. The group is the most important thing for me and I value and prioritise building an environment where people feel heard.

4) If you could, what advice would you give to yourself back when you were a PhD student?

Quality over quantity. I published relatively many papers as a PhD student, but looking back on it, it would have been better to go into more mechanistic detail to fully unravel new biology. In my group, I would ideally like the PhD students to work on one big project that leads to a meaningful and insightful discovery, rather than publishing a much less mature paper. But of course, it’s tricky because each student needs to present at least one publishable chapter in their thesis, and time might be limited.

It is also important to remember: A PhD is a learning trajectory. You’re learning, you’re growing into becoming an independent scientist. You’re not an independent scientist yet, nor are you immediately working at your full strength when you start. You will be when you’re close to finishing. You will know all the ins and outs of your lab. You will know all the different research lines. You will have a ton of new knowledge, a ton of technical know-how. And then it’s time to move on.

5) The last question is about Imposter Syndrome, which is quite common among PhD students. We wondered if you ever felt that, and how it evolved as you progressed in your career?

Yes, absolutely. I think most people experience impostor syndrome to some extent. What helped me was realizing that no one knows everything, and comparing myself to others in a realistic way, recognizing that even successful people have gaps in their knowledge.

You don’t have to meet every requirement perfectly to deserve your role; growth happens along the way. Seeking feedback and reflecting on how much you’ve learned and achieved over time can build confidence. In a PhD, progress often feels slow day-to-day, but a year of growth can be substantial.

No one can be an expert in everything. In our group, our bioinformaticians and lab scientists now surpass my own skills in their specialties! This is what makes up a great team. One person can’t be great at everything.

Over time, as you gain experience, you naturally become someone others turn to for advice. That gradual shift helps diminish impostor feelings, though they may never fully disappear — just like nerves before a big presentation. And that’s okay; it’s part of growing professionally.