When these LN cells were stimulated by anti-CD3 with or without anti-CD28 antibody (Ab), more IL-17A was secreted by LN cells of CD4CreTTPf/f mice than that of WT mice (Figure 1F), suggesting a correlation between IL-17 and the development of dermatitis in the aging CD4CreTTPf/f mice. This evidence concerns the gene IL17A and dermatitis.