STAT3 and lung cancer: ALK rearrangement in lung cancer has been reported to induce STAT3 signaling and upregulate immune checkpoint protein programmed cell death-ligand 1 (PD-L1).36,37 Because our results above indicated RDAA lung cancer cells harbor similar function and downstream signaling to those with ALK rearrangement, we asked whether RNase1-induced ALK activation also enhances STAT3 signaling and PD-L1 expression.