TP53 and breast carcinoma: When we examined the endogenous expression levels of Hsp90, Hsp70, Akt, and p53 in the breast cancer and normal cell lines, the expression levels of Hsp90 and Hsp70 in these cell lines were equally unremarkable, except for those in the MDA-MB-231 cells, but the expression levels of Akt and p53 were obviously different among these cell lines (Figure 1B).