When we examined the expression levels of Hsp70, Hsp90, and Akt, which is one of the client proteins of Hsp90 in GB cell lines, it was found that the endogenous expression levels of these proteins were equally unremarkable, and that PTEN was lost in these GB cells compared with the other cancer and normal cell lines (Figure 1B and Additional file 1). This evidence concerns the gene AKT1 and cancer.