ADK and breast carcinoma: Recent direct measurements of AK-mediated metabolic flux indicate that cancer cells have suppressed ATP β-phosphoryl energetics and AMP signaling, as indicated from 18O-labeling experiments demonstrating that highly aggressive breast cancer cells MDAMB231 have lower β-ATP[18O] turnover (AMP phosphorylation) than have the control MCF10A cells (Klepinin et al., in preparation).