In the patients with AHH or autoimmune hypoparathyroidism reported by other researchers, the patient sera were found to be reactive against several peptides that can be found in the CaSR-ECD (peptides 41–69; 114–126; 171–195; 214–236; 344–358; and 374–391) (29, 31, 33–36, 38). Here, CASR is linked to autoimmune hypoparathyroidism.