TGFB1 and neoplasm: While several studies have associated this conversion with the enhanced production of VEGF [125] and have shown that NK-derived VEGF is a critical regulator of tumor vascularization and growth in mouse models [126], in vitro studies examining the discrete effects of TGFβ and hypoxia on cultured human peripheral NK cells have shown that VEGF production is largely hypoxia dependent and is not enhanced by the process of TGFβ-mediated NK cell conversion [124].