The most interesting and novel finding in the current investigation came from Lo-expressor TSHR-A-subunit transgenics that developed thyroiditis after immunization with CFA+A-subunit protein followed by A-sub-Ad: when examined at euthanasia, sera from some of these mice had antibody binding to TSHR peptides not present in the immunogen, namely peptides S, Z and EC1 downstream of the A-subunit, and only represented by the naturally occurring mouse TSHR in vivo. Here, TSHR is linked to thyroiditis.