CD1A and keloid: CD1a-positive Langerhans cells were localised close to the basal layer of the epidermis in the normal skin (Fig. 3A, N2 and Supplementary Fig. S2); however, in both keloid types, they were broadly distributed within the epidermis, with an increased number of cells observed (Fig. 3A, KA5 and KE4 and Supplementary Fig. S2).