It has been reported that the SUMO4 A+163G (M55V) polymorphism is an essential polymorphism involved in regulating its own sumoylation, and it has been shown to be associated with certain autoimmune diseases such as type 1 diabetes, autoimmune thyroid disease, and rheumatoid arthritis without amyloidosis [19]. Here, SUMO4 is linked to autoimmune thyroid disease.