To explore the epigenetic mechanism of ROBO4 expression further, we examined the methylation level in the promoter region of ROBO4, and our in vivo and in vitro results confirmed that hyperglycemia could induce hypomethylation of most CpG sites in the ROBO4 promoter, and thereby affect ROBO4 transcription. The gene discussed is ROBO4; the disease is Hyperglycemia.