Upon tamoxifen treatment, Cre simultaneously inactivates two (floxed) alleles of the tumour suppressor Pten and induces mutant Kras. The new model allows PDA and its associated cachexia to be induced only after ending of neonatal growth of mice, creating a condition that more accurately reflects the actual loss of muscle (and adipose) tissue in patients with PDA.99 This evidence concerns the gene KRAS and Patent ductus arteriosus.