This role was definitively demonstrated by the identification of 13 inborn errors of IL-17 immunity, including AD IL-17F and JNK1 deficiencies and AR IL-17RA, IL-17RC, and ACT1 deficiencies, in particular, all of which impair or abolish IL-17A/F signaling and are associated with CMC (Puel, 2020). Here, IL17A is linked to Alzheimer disease.