The intensity of P2X7 immunoreactivity in cross sections of skin cancers was significantly weaker than in normal (Fig. 7A) and in papilloma tissues (Figs. 10A, B), but it did not differ among the DMBA/TPA and DMBA/TPA+BzATP groups (Figs. 10E, F). The gene discussed is P2RX7; the disease is skin neoplasm.