Fu et al. [64] discovered that ATL II can inhibit the expression of p-STAT3, p-Src, Mcl-1, and Bcl-xL in cancer cells, while overexpression of STAT3C, a constitutively active variant of STAT3, reduced the effect of ATL II, implying that it may inhibit STAT3 signaling to produce an anti-melanoma. This evidence concerns the gene STAT3 and cancer.