CYC1 and atrial fibrillation: Furthermore, the majority of the identified proteins are in fact involved in contractile function (MYL4, MYL7, TNNC1 and TCAP) or metabolism (PPIF, CKM, AK1, PGAM2, CYC1, ETFB and ALDOA), two mechanisms linked to processes involved in the pathophysiology of AF.