RBM20 and familial dilated cardiomyopathy: The latest research about using hiPSCs for the study of circRNAs in DCM declares that if there is no RBM20 mutation detected when the phenotype resembles the phenotype of DCM with arrhythmias as observed in RBM20 mutation carriers, it is necessary to consider variants in the I-band region (Tijsen et al., 2021) because hindering formation or function of these TTN circular RNAs which stem from the I-band region also may have the DCM clinical phenotype.