With regard to ubiquitination, ring finger protein 20 (RNF20), an E3 ligase critical for the monoubiquitination of histone H2B at lysine 120 (H2Bub), is essential for adipose tissue homeostasis, as its adipocyte-specific deletion in mice results in progressive fat loss, organomegaly, and hyperinsulinemia [175]. Here, RNF20 is linked to hyperinsulinism.