One problem with this, as pointed out by some reviewers on my first Cancer Research UK application, was that the tumour progenitor cells were likely to express both the α1 and α2 isoforms of AMPK, so the project would require combining five mutant alleles by mouse breeding (one lox-STOP-lox allele to switch on the K-Ras oncogene, plus two floxed alleles for each of the α1 and α2 genes to knock them out). Here, PRKAA2 is linked to cancer.