Histological sections, prepared from control (CTL) mouse skin and mouse skin 1–5 days post NM exposure, were stained with hematoxylin and eosin, which stains nuclei blue/black, and keratin and cytoplasm red. One representative section from 3 mice/treatment group is shown (original magnification, × 400). E, epidermis; D, dermis; S, sebaceous gland; HF, hair follicle; asterisk, eschar, Ac, acanthosis. Black arrow, loss of stratum corneum; black arrowhead, inflammatory cell infiltrate. Left panels, mouse skin treated with NM; right panels, mouse skin treated with NM and 4338.