TNNI3 and myocarditis: In addition to MyHC, several other heart-specific proteins such as adenine nucleotide translocator 1 (ANT1), β1-adrenergic receptor (β1AR), cardiac troponin I (cTnI), muscarinic M2 receptor (M2R) and sarcoplasmic/endoplasmic reticulum Ca2+ adenosine triphosphatase 2a (SERCA2a) have been proposed as autoantigens that can activate cellular and humoral immunity, leading to myocarditis development19,20.