In combination with gamitrinib treatment, inhibition of Grp94 was sufficient to elevate cytoplasmic calcium concentrations (Fig. 4d; Supplementary Fig. 4b, c), suggesting that cancer cells require the chaperone activities of Grp94 and TRAP1 to maintain cellular calcium homeostasis by preserving the proteostasis of respective organelles. The gene discussed is HSP90B1; the disease is cancer.