Fujita et al. and Wölfle S.J et al. reported that IL-8 produced by cancer cells stimulates CD163+ M2-TAMs to produce IL-10, which, in turn, leads to the phosphorylation of STAT3, and then IL-10/STAT3 signaling induces PD-L1 overexpression [43, 44]. Here, STAT3 is linked to cancer.