RRAS and autoimmune disease: HCP5 polymorphisms have been associated with autoimmune disorders, leading to the hypothesis that HCP5-related disruption of immune response can contribute to childhood obesity; HCP5 functions as a competing endogenous RNA (ceRNA) binding to miR17-5p and increasing Ras-related protein R-Ras (RRAS) protein expression in the MAPK signaling pathway, which regulates adipocyte carbohydrate metabolism, thus, promoting childhood obesity development [106].