HIF1A and neoplasm: This promotes cell survival by degrading damaged mitochondria and preventing the accumulation of reactive oxygen species (ROS).[64] Additionally, hypoxia impairs cytotoxic T cell function and promotes the recruitment of regulatory T cells, lowering tumor immunogenicity.[40] The activation of HIF1A triggers signaling cascades that impair nitric oxide signaling, leading to the shedding of MHC class I chain‐associated molecules.