Importantly, B cells play a vital role in the etiology of DCM as they are capable of synthesizing antibodies against cardiac proteins, including β1 adrenergic receptor (β1-AR), myosin heavy chain (MHC), adenine nucleotide translocator (ANT), and others [136,137,138]. The gene discussed is ADRB1; the disease is familial dilated cardiomyopathy.