TPR and breast cancer: As shown in Figure 3A and B, treatment of BT20 and MDA-MB-231 breast cancer cells with Antp-TPR in the presence of R11-Hsp70 effectively decreased the expression of Hsp90 client proteins, including Akt, p53, and cRaf, compared with that of Antp-TPR or R11-Hsp70 alone, or untreated control cells, although 10 μM of R11-Hsp70 alone caused the slight decrease of these proteins in BT20 cells, and high concentration of R11-Hsp70 (40 μM) alone also caused the decrease of expression levels of Hsp90, Hsp70, Akt, and p53 proteins in BT20 cells (Additional file 2).