TGFB1 and neoplasm: On the other hand, transforming growth factor β (TGF-β) produced by tumor cells polarizes neutrophils to an N2 phenotype, which is distinguished by increased expression of Olfactomedin 4 (OLFM4) and the chemokines CCL2, 3, 4, 8, 12, and 17, and CXCL1, 2, 8, and 16 [150,153,154].