Further, MDAMB231 and BT 474 cells stably expressing the nonphosphorylatable mutant of PEA15 were also markedly impaired in their tumor-forming potential compared to WT PEA15-expressing cells (Figure 5C and D), together suggesting that AMPK activation and PEA15 phosphorylation are both necessary for tumor formation by breast cancer cells. Here, PEA15 is linked to breast carcinoma.