FKBP1B and catecholaminergic polymorphic ventricular tachycardia: Since FKBP12.6 is presumed to stabilize RyR2 channels in their closed state (a contentious issue by itself [27,28]), a FKBP12.6-free RyR2 channel would dwell in the open state for longer times, generating the excessive Ca2+ leak which is at the center of the pathogenic mechanisms of CPVT mentioned above.