Immunosuppressive factors such as HIF-1α, CD73, and PGE2 (Prostaglandin E), along with immunosuppressive cell populations including tumor-associated macrophages (TAMs), regulatory T cells (Tregs), and myeloid-derived suppressor cells (MDSCs), have been shown to be present in the prostate cancer immune microenvironment and may contribute to immune evasion (171–175). The gene discussed is HIF1A; the disease is prostate cancer.