Join Gitte Zels, a PhD student and Resident in Anatomic Pathology at KU Leuven, as she discusses her ILC23 poster titled “Overview of patients with invasive lobular breast carcinoma included in the post-mortem tissue donation program, UPTIDER.” The discussion will focus on the role of tumor heterogeneity in metastatic breast cancer, particularly in invasive lobular breast cancer (ILC). She will introduce the post-mortem tissue donation program led by the Laboratory for Translational Breast Cancer Research in Belgium, highlighting its importance in advancing cancer research and providing insights into the complexities of metastatic disease. The session will provide an overview of the program’s procedures and aims to spark a dynamic conversation with patient advocates.