HIF1A and diabetes mellitus: Upstream regulator analysis suggested COMMD1, HIF1A, EGLN, PIK3R1 and MTORC1 as major upstream regulators for the phase shifts, while HSP90B1, YWHAZ, CNGA3, COL2A1 and TFRC (Fig. 5B) were identified as the major upstream regulators for the amplitude changes observed in the diabetic retina.