RNF216 and aceruloplasminemia: RNF216 is a broadly expressed RBR E3 ligase, and loss‐of‐function mutations in RNF216 are linked to neurodegenerative conditions such as Gordon–Holmes syndrome (GHS) and Huntington‐like disorders, characterized by hypogonadotropic hypogonadism, cerebellar ataxia, and dementia.44, 45, 46