The highly conserved HSPC/HSP90 family comprises 5 members HSPC1/HSP90AA1 (cytosol inducible), HSPC2/HSPAA2 (cytosol inducible), HSPC3/HSPAB1 (cytosol constitutive), HSPC4/GRP94 (ER), and HSPC5/TRAP1 (mitochondria), but most of the studies in DM complications were performed on the cytosolic members of this family. The gene discussed is TRAP1; the disease is diabetes mellitus.