In the AD-like skin lesions, Dfb-treated HrasG12S/+ mice displayed increased number of mast cells (toluidine blue+ and tryptase β1+), a marked increase in the numbers of T cells (CD4+) and dendritic cells (MHC class II+) (Fig. 2a, b and Supplementary Fig. 2c, e). The gene discussed is CD4; the disease is Alzheimer disease.