Although not examined in the context of the onset of diabetic retinopathy, Rac1 functions have also been shown to be regulated by RNA splicing and other post-translational modifications such as ubiquitination, adenylation, phosphorylation and SUMOylation [64,65], and mutations of Rho GTPases (e.g., Cdc42, Rho and Rac1) have also been reported in pathological states, including immonodeficiency and cancer [64]. This evidence concerns the gene RAC1 and diabetic retinopathy.