Since the JAK1/2 kinase family has been reported to mediate PD-L1 expression on extracellular stimulation in tumor cells,38 we first investigated the effects of ruxolitinib (a JAK inhibitor) on the expression of PD-L1 in pemetrexed-treated CL1-5 and CL141 cells. Here, JAK1 is linked to neoplasm.