PRF1 and neoplasm: I. Tumors with a predominantly anti-tumor TIME, characterized, among other factors, by a high number of CD8 + cytotoxic T cells (CTLs) and other lymphocytes such as CD4 T helper cells, natural killer (NK) cells, regulatory T cells (Tregs), B lymphocytes, plasmocytoid dendritic cells as well as elevated levels of granzyme and perforin.