HIF1A and neoplasm: For instance, in addition to our finding that CAF-secreted TGF-β signaling and hypoxic environment-induced HIF-1α synergistically induce GLI2 expression to regulate tumor stemness and chemoresistance, it is well known that TGF-β signaling plays a vital role in tumor immunity in the TME by repressing the antitumor functions of various immune cell populations, including T cells and natural killer cells [51].