HSPA9

HSPA9, a member of the heat shock protein family A (Hsp70), has alternative names including CSA, MOT, MOT2, SAAN, CRP40, EVPLS, GRP75, PBP74, GRP-75, HSPA9B, SIDBA4, MTHSP75, HEL-S-124m. HSPA9 is primarily localized in mitochondria but is also present in the endoplasmic reticulum, plasma membrane, and cytoplasmic vesicles, making it a heat shock homologous protein. HSPA9 plays a role in cell proliferation, stress response, and mitochondrial maintenance; it can intervene in apoptosis pathways and acts as a regulator of peroxisomal autophagy within cells. The absence of HSPA9 enhances degradation through peroxisomal autophagy. HSPA9 is highly expressed in various tumors and is closely associated with tumor cell proliferation and invasion, serving as an independent clinical predictive marker.