CD8A and melanoma: For example in melanoma, head and neck, breast, bladder, urothelial, ovarian, colorectal, and lung cancer, a high density of CD3+ T cells, CD8+ cytotoxic T cells, and memory T cells (CD45RO+) was correlated with favorable disease-free survival (DFS) and overall survival (OS) [4, 12, 19], as well as a lower probability of metastatic spread and progression-free survival (PFS) [10, 20, 21] with a few exceptions, e.g., in clear cell renal cell carcinoma (ccRCC) [17, 22–24].