Such a discrepancy must have been due to the soluble factor expressed by E.G7 lymphoma cells as tumor evasion mediated by B16 melanoma was known to involve the production of IL-1026, TGF-β and VEGF27 as well as surface expression of programmed cell death ligand 1 (PD-L1)28. Here, TGFB1 is linked to melanoma.