Although CD4+ T cells from HBZ-Tg mice and HBZ-Tg/IFN-γ KO mice were similar in their migratory responses to CXCL10, their abilities to infiltrate tissues in vivo may differ, because the HBZ-Tg/IFN-γ KO mice did not develop dermatitis to the same degree that the HBZ-Tg mice did. The gene discussed is CD4; the disease is skin disorder.