Under hypoxic conditions, HIF-1alpha leads to anupregulation of PD-L1 expression on MDSCs in the tumor microenvironment, thereby increasing interleukin (IL)-6 and IL-10 secretion from MDSCs, causing a MDSC-induced immunosuppression, T cell inactivation, and promoting tumor progression [17, 18]. This evidence concerns the gene IL10 and neoplasm.