More recently, to establish a more precise localization of the epitope responsible for the production of cardiomyopathy-inducing autoantibodies, a cyclic peptide corresponding to β1-AR ECL2 was used, which made it possible to identify the key molecular determinants of this epitope, including the NDPK211–214 segment and the C209–C215 cysteine bridge. The gene discussed is ADRB1; the disease is cardiomyopathy.