Recipient Langerhans cells are not required for clinical or histologic GVHD in the C3H.SW→B6 model. Tg⁺ and Tg⁻ hosts were irradiated and reconstituted with C3H.SW BM with or without 2-3 × 10⁶ purified C3H.SW CD8 cells. Shown are data from 1 of 2 experiments with comparable results. Tg⁺ and Tg⁻ CD8-recipients had similar weight change (A; P > .170 comparing Tg⁺ and Tg⁻ CD8 recipients at all time points; P < .01 comparing each CD8 group to its respective BM alone control from day +20 onward), incidence of clinical skin disease (B; P = .299 comparing Tg⁺ and Tg⁻ CD8 recipients; P < .001 comparing each CD8 recipient to its BM alone control), and number of skin ulcers (C). (D) GVHD pathology scores in skin, ear, liver, and colon. The P values for number of skin ulcers and pathology scores are shown in the figure.