FAS and neoplasm: Moreover, the presence of the suppressive cytokine IL-10 and prostaglandin E2 (PGE2) contributes to the upregulation of the FasL molecule on endothelial cells, leading to apoptosis of CD8+ cytotoxic T cells and inhibition of tumour microenvironment (TME) infiltration by T effector cells in Fas/Fas-L (CD95) [351,352,353,354,355].