BAP1 is a tumor suppressor gene that is lost or deleted in diverse cancers, including uveal melanoma,[1] malignant pleural mesothelioma (MPM),[2] clear cell renal carcinoma,[3] and cholangiocarcinoma.[4] Recently, BAP1 germline mutations have been reported in families with combinations of these same cancers. This evidence concerns the gene BAP1 and cholangiocarcinoma.