ACTA1 and colitis: For example, in a colitis model induced by the transfer of CD4+CD45RBhigh cells into severe combined immunodeficient (SCID) mice, a subpopulation of colonic CD40+CD90+αSMA− MCs was shown to secrete higher amounts of IL-6, CCL2, and CCL5 in response to interferon-γ (IFN-γ) and CD40L [42].