In addition, the knockdown of HIF-2α but not HIF-1α decreased the expression of circHIPK3 in GC under a hypoxic microenvironment, and a strong positive correlation was also verified between HIF-2α and circHIPK3 in GC samples, indicating that circHIPK3 was a potential target of HIF-2α. This evidence concerns the gene HIF1A and gastric cancer.