TGFB1 and neoplasm: It has been postulated that NK cells are critical to the prevention of cancer development (elimination and equilibrium); however, once the tumor microenvironment is established (escape), suppressor factors such as TGF-β and IL-10 are induced and negative inhibitory receptors, such as the T-cell immunoglobulin-and-mucin-domain-containing molecule-3 receptor (TIM-3) on NK cells, that maintain an NK-cell anergic state (40) are upregulated.