Currently, a number of E3 ligases that have been linked to AD pathology, several of which were described in the previous section, have been crystallized and have solved structures: CHIP, NEDD4-1, TRAF6, Parkin, HRD1, Ube3A (E6AP), Itch, and MARCH8 (Table 1). Here, PRKN is linked to Alzheimer disease.