We tested the IC50 for TPZ in 1205Lu melanoma cells expressing an empty plasmid and has low gap junction coupling (GJIC), (1205LuP), overexpressing wild type connexin43 which have high GJIC, (1205LuC), and overexpressing a dominant negative connexin 43 which have essentially no GJIC, (1205LuT) (Figure 1E, 1F). The gene discussed is GJA1; the disease is melanoma.