M2-TAMs can promote tumour progression by both soluble mediators (e.g. Arginase [Arg]1-derived products and transforming growth factor beta [TGFβ] release) and surface receptors (e.g. expression of programmed death-ligand 1 [PD-L1]), resulting in suppression of anti-tumour response [21]. The gene discussed is TGFB1; the disease is neoplasm.