CACNA1C and clostridium difficile infection: The differential effect on IBa, ICa, and CDI by the K1662E versus I1654A mutation is consistent with the differential effect of the K1662E versus I1654A mutation on Po (15) and suggests that formation of a complex of CaV1.2 with half Ca2+-saturated Ca2/CaM is important for Po and for predisposing CaV1.2 to CDI.