CTLA4 and cutaneous melanoma: Regarding the Pathology Atlas (https://www.proteinatlas.org/humanproteome/pathology), comprised of 5 million immunohistochemistry (IHC) images of different types of cancer, we compared the IHC data of the three novel ICP related genes and 5 classical checkpoint genes (ICPs) (CTLA4 is not available in this database) in CRC, breast cancer (BC), stomach cancer (STC) and skin cutaneous melanoma (SKCM).