Attending the 2026 Butterfly Winter Training School was an eye-opening experience, offering a deep dive into the world of immuno-oncology and cutting-edge pediatric cancer research. As a third-year PhD student in clinical neuropsychology, the immune-oncology focus gave me a valuable opportunity to step outside my own field and gain insight into the broader landscape of pediatric oncology research.

The two-day program brought together the 28 Butterfly PhD students, each researching different aspects of pediatric oncology, and featured talks from leading experts in both basic science and clinical practice. On the first day, speakers Zsolt Sebestyén and Sjoerd van der Burg explored how the tumor microenvironment shapes immune responses and how these mechanisms can be harnessed for novel immunotherapies. Advanced imaging and high-throughput screening techniques were highlighted by Kristof Van Avondt and Edo Elstak , showing how technological innovation is transforming cancer research. Sessions on PhD planning and lab sustainability, led by Anke Hammerschlag and Joep Sprangers , offered practical guidance and perspectives on responsible research practices. The day ended with a social dinner at Humphrey’s Utrecht , which allowed us to connect as an international cohort and reflect on the day’s discussions.

The second day focused on translating scientific discoveries into clinical applications. Max Wellenstein shared the latest in antibody-drug conjugates, Friso Calkoen introduced CAR-T cell therapy, and Moniek de Witte spoke about stem cell transplantation and patient quality of life. Insights into leukemia biology and the tumor immune microenvironment were provided by Monique den Boer and Lindy Visser , highlighting how understanding complex cellular interactions can inform new therapeutic approaches.

While much of the content was outside my direct area of ​​research, I found the sessions on stem cell transplantation and sustainable lab practices particularly inspiring. The training school challenged me to think about my own work in the context of the wider pediatric oncology field and underscored the value of interdisciplinary learning and collaboration.

The Butterfly Winter Training School once again demonstrated the strength of the program: uniting young researchers from diverse backgrounds to learn from leading experts, explore innovative research, and contribute to improving outcomes for children with cancer. I, and I’m sure many others, left the training school feeling inspired and looking forward to future opportunities to continue learning from colleagues across disciplines within the Butterfly program.