PIK3CA and breast cancer: The depletion of Hsp70 was also shown to sensitize myc-overexpressing lymphoid cancer cells to drug-induced apoptosis [31], moreover, inhibition of Hsp70 synthesis by transfection of antisense Hsp70 cDNA results in massive death of human breast cancer cells [32] and caused senescence in cells transformed with RAS, Her2 or PIK3CA oncogenes [33].