STAT3 and lung cancer: In addition to NF‐κB, STAT3 is another key factor in IL‐6 signalling pathway,34, 35 and it has been documented that IL‐6 promoted lung cancer development and progression by activating STAT3.36, 37 Another study found that IL‐6 could induce immunosuppressive factor PD‐L1 expression on peripheral myeloid cells through STAT3‐dependent mechanism.38 However, we did not observe the significant change of IL‐6‐inducing elevated TIM‐4 expression in STAT3 inhibitor treatment group.