Interestingly, Foxp3-Cre Pak2-deficient mice succumbed to death within 7–8 weeks after birth following the development of a more severe inflammatory disease compared to Cd4-Cre Pak2-deficient mice, evident by their runted size and the development of dermatitis, with multiple skin lesions apparent on the back, abdomen, tail and ears (Fig. 1a,b). This evidence concerns the gene CD4 and dermatitis.