The annual B cell winter school of the IRTG TRR130 is a 5-3-day long research retreat. It gives the PhD students the possibility to present and critically discuss their thesis projects and is one of the most important intercity activities. The meeting serves predominantly as a research-in-progress platform for PhD students. However each winter school is complemented by lectures on the most important concepts in B cell immunology and related topics by external speakers and TRR130 members.