Chaudhry et al. (2009) disclosed further that STAT3 is fundamental for the inhibition of Treg cells development and Th17 differentiation. In fact, the STAT3 transcription factor, in collaboration with NFκB, regulates the expression of these genes encoding critical cancer-promoting inflammatory mediators, establishing a crosstalk between cancer and immune cells of the microenvironment and perpetuating the effects of STAT3 activation in cancer cells (Yu et al., 2007; Grivennikov and Karin, 2010; Yang et al., 2019). This evidence concerns the gene STAT3 and cancer.