MTAP and cholangiocarcinoma: According to the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) database, MTAP deletion is most frequently observed in patients with mesothelioma (33.1%), urothelial carcinoma (23.8%), central nervous system tumors (19.0%), pancreatic cancer (18.4%), cholangiocarcinoma (15.6%), thymomas (15.7%), and non-small-cell lung cancer (14.3%) [8].