CD274 and lung adenocarcinoma: In contrast, in vitro trials in lung adenocarcinoma cases found no reduction in PD-L1 expression by tumor cells after blockade using inhibitors of mTOR, MEK1/2, JAK1/2, or STAT3/5 alone, suggesting that achieving complete regulation of PD-L1 expression may require simultaneous blockade of several FGFR downstream pathways [23].