ARID1A and angiosarcoma: By analyzing the AACR GENIE dataset, we identified recurrent alterations in pathways central to angiosarcoma, including TP53, VEGF (KDR/FLT4), and PI3K (PIK3CA), as well as tumor suppressors such as ATM and ARID1A, chromatin remodelers like KMT2D, and regulators of contact inhibition such as FAT1.