Moreover, our previous study [Chang et al.: Arecoline decreases interleukin-6 production and induces apoptosis and cell cycle arrest in human basal cell carcinoma cells (BCC/KMC), submitted] showed that, in basal cell carcinoma cells, arecoline reduces levels of the tumor cell survival factor IL-6, increases levels of the tumor suppressor factor p53, and elicits cell cycle arrest, followed by apoptosis, showing that arecoline interferes with cancer cell cycle progression. This evidence concerns the gene TP53 and basal cell carcinoma.