TGFB1 and neoplasm: On another hand, M2-like macrophages co-cultured with PDA cells remain to have a M2-like phenotype with an increased expression of M2 markers, likely secondary to the effect of tumor-derived TGFβ-1 as previously suggested.27 Nevertheless, the mechanism for the upregulation of some of the M1 markers in M2-like macrophages remains to be elucidated.