However, CD4+ T cells that fell in none of these categories were by far the predominant CD4+ cell population that were IL-10GFP+ in the skin after infection, representing more than 60% of all IL-10GFP+ CD4+ T cells in both 1x and 4x DEC (Fig 3D), as well as increasing in number significantly in 4x DEC (Fig 3E, p<0.0001). Here, CD4 is linked to infection.