FKBP1B and catecholaminergic polymorphic ventricular tachycardia: Wehrens et al. and Marks suggested that a RyR2-binding protein, calstabin 2 (FKBP12.6), stabilizes RyR2s in wild-type myocytes in which CPVT-linked mutations in FKBP12.6 can disassociate from the RyR2 [16,17].