Fibroblast growth factor receptor substrate 2 (FRS2) and B7-H3/CD276 are both highly expressed in medulloblastoma (MB) patient samples. While FRS2 has been shown to drive an invasive tumor phenotype, the biological role of B7-H3/CD276 is still incompeletely understood. Here, we explored the interactome of FRS2 and B7-H3/CD276 in MB cells stimulated with bFGF. Further, we studied the treatment impact with the FRS2 small molecule ligand C7 on both interactomes, as well as the effect of chloroquine on the interactome of B7-H3/CD276. Towards this aim, we expressed mNeonGreen-tagged FRS2 and B7-H3/CD276 in UW228 cells and isolated direct interactor proteins via pulldown using mNeonGreen-trap magnetic agarose beads. We performed mass spectrometry and quantified relative abundances compared to pulldowns from wild type UW228 cells.