HIF1A and gastric cancer: Experts identified that upregulation of PD-L1 is involved in tumorigenesis and poor prognosis in gastric cancer.21 As another HIF-1α target, hexokinase is one of the rate-limiting enzymes of glycolytic pathway.22, 23 In mammals, there are four subtypes of hexokinase, the type II hexokinase is insulin sensitive and mostly overexpressed in poorly differentiated tumor tissues.24 Another rate-limiting enzyme of glycolytic pathway is PFK-1 (phosphofructokinase 1), a putative transcriptional target of HIF-1α.