Three breast cancer cells had high levels of AKT phosphorylation (p-AKTHigh) due to activation by HER2 amplification (SKBR3 and HCC1569) or PTEN loss (MDAMB468), whereas MDAMB231 and the immortalized mammary epithelial cell MCF-10A expressed low levels of p-AKT. The gene discussed is PTEN; the disease is breast carcinoma.