TGFB1 and neoplasm: While the tumor-secreted transforming growth factor (TGF-β) was shown to transform N1 TANs (tumor-suppressive phenotype) to N2 TANs (tumor-promoting phenotype) [23–25], the N2→N1 transition can be mediated by type I IFN [14, 23, 26, 27] (Fig 1).