HSPA9 and cancer: Indeed, knockdown of the gene HSPA9 by ribozyme or siRNA reduces cell growth and viability of human cancer cells.98,99 Disrupting the interaction between GRP75 and p53 by the potent anti-cancer drug, MKT-077,100 or GRP75 binding peptide, activates endogenous p53, thus preventing cell growth of osteosarcoma and breast carcinoma cells.88