PRKAA1 and cancer: Thus, AMPK is a ‘double-edged sword', initially acting as a tumour suppressor that protects against cancer but then, once cancer has arisen due to gain/loss-of-function mutations in other oncogenes/tumour suppressors, switching to become a promoter of tumour growth, most likely by protecting cancer cells against genotoxic and other stresses that might otherwise cause cell death.