PTEN and breast cancer: Tetrocarcin A (51) was later found to directly induce apoptosis in breast cancer cells accompanied by activation of a proteolytic cascade of caspases and a concomitant decrease in phosphorylation of protein kinase B, pyruvate dehydrogenase kinase-1, as well as phosphatase and tensin homolog (Akt, PDK-1, and PTEN, respectively) [93].