Metabolic analysis of AMP concentrations in LKB1−/−NIC tumors (0.001 ± 0.00 μM/mg), NIC tumors (0.13 ± 0.05 μM/mg) and WT (0.59 ± 0.14 μM/mg) mammary tissues indicate that AMP concentrations are significantly reduced in mammary tumors compared to WT tissue (P<0.05). The gene discussed is STK11; the disease is breast cancer.