CACNA1C and clostridium difficile infection: CaV1.2 channel opening promotes a rise in intracellular Ca2+ sensed by CaM that causes a Ca2+-induced conformational change in the CaM/CaV1.2 complex leading to CDI (Ben Johny et al. 2013; Peterson et al. 1999; Zuhlke et al. 1999).