CACNA1D and Parkinson disease: While the contribution of Cav1.3 channels to PD is undeniable, it is important to point out that Isradipine has, in fact, a higher affinity for Cav1.2 channels (Koschak et al., 2001; Lipscombe et al., 2004; Olson et al., 2005; Xu and Lipscombe, 2001).