STAT3 and breast carcinoma: On the other hand, the phosphorylation of AKT(S473), EGFR(Y1068), ErbB2/Her2(Y1248), PDGFR(Y716), Shc(Y239), and Stat3(S727) were elevated only in MDA-MB-468 breast cancer cells, but retained basal level in MCF-7 cells compared to HMEC and TERT (Table 1).