RNF121 and diabetic kidney disease: Three of these genes were hypermethylated: CALD1, RNF121, and MSI2. The CALD1 was previously related to diabetes nephropathy (43), while the role of RNF121 in the VEGF‐induced endothelial cell proliferation inhibition has been associated with diabetic retinopathy and age-related macular degeneration (44).