The failure of exogenousPGE2 to restore PD-L1 expression levels in NAF COX-2KD may suggestdistinct actions of autocrine and paracrine PGE2, or indicate a role forother COX-2-derived products, in tumor cell COX-2 mediated control of PD-1 expression.The pathways through which COX-2-derived PGE2/other prostanoids control tumorcell expression of PD-L1 and other immune modulators are currently underinvestigation. Here, CD274 is linked to neoplasm.