Moreover, Kinoshita et al. (2020) also reported that the combined secretion of TGF-β1and interleukin 6 (IL-6) by cancer cells induced a heterogeneity of Tregs and/or interleukin 17 (IL-17)-producing T helper 17 cells, favoring the progression of biliary tract cancer cells. The gene discussed is IL17A; the disease is biliary tract neoplasm.