PRKAA1 and breast cancer: To determine the clinical importance and relevance of the AMPK-Skp2-Akt axis in human breast cancer, we performed immunohistochemistry (IHC) to detect Skp2 S256 phosphorylation pSkp2 (S256), AMPK T172 phosphorylation (pAMPK) and Akt S473 phosphorylation (pAkt) in 208 patients with various stages of breast cancer.