In AD, abnormalities in Parkin (an E3 ligase), ubiquitin C‐terminal hydrolase L1 (UCH‐L1) (a DUB), HRD1 (an E3 ligase), and the C‐terminus of Hsc70‐interacting protein (CHIP) (an E3 ligase) have been reported. This evidence concerns the gene STUB1 and Alzheimer disease.