We reconfirmed our previous data showing that abrogation of STK33 following incubation of cancer cells with PU-H71, an ATP-competitive HSP90 inhibitor currently under investigation in clinical trials [31, 32], results in augmented cell death as demonstrated by increased levels of cleaved PARP in western blot analysis (Supplementary Figure 3A). This evidence concerns the gene HSP90AB1 and cancer.