STAT3 and neoplasm: Specifically, proinflammatory cytokine IL-6 induces Twist1 expression in normal fibroblasts via STAT3 phosphorylation, and Twist1 then promotes the transdifferentiation of normal fibroblasts to CAFs via activation of a strong tumor-promoting chemokine, CXCL12, as well as suppression of senescence [10].