P2RX7 and melanoma: The P2X7 receptor is expressed on a number of cancer types including, but not limited to prostate, lung, kidney, colorectal, gastric, breast, cutaneous squamous-cell and basal-cell carcinomas, melanoma, leukemia, neuroblastoma, glioma, ovarian, cervical, bladder, papillary thyroid, pancreatic and bone cancer.