A histopathological study by Harvell et al. examined the CD4/CD8 ratio in various dermatoses (psoriasis, spongiotic dermatitis, PLEVA, lichen planus, lichen sclerosus, herpetic dermatitis, erythema annulare centrifugum, urticaria, normal skin) [36]. The gene discussed is CD4; the disease is lichen planus.