PRF1 and neoplasm: Intriguingly, decreased gene expression of both pro- (Il-1β and Il-6) and anti-inflammatory (Il-10 and Tgf-β) players, as well as T CD8+ dependent effector function genes such as granzyme (Gzma) and perforin (Prf1) in TME of Opn4KO was found when compared to Opn4WT tumor-bearing mice (Fig. 1 o–t).