HSPA9 and heart failure: It is well known that Ca2+ played a detrimental role in heart failure and myocardial ischemia/reperfusion, and Ca2+ overload activated the complex matrix chaperone procyclin D (CypD), which regulated the VDAC1, Grp75, and IP3R1 complex and thus caused damage to cardiomyocytes, whereas inhibition of the CypD, VDAC1, Grp75, and IP3R1 complex could protect cardiomyocytes49.