The UCLA, Adolescent Smoking Cessation Center (ASCC) provides a comprehensive research program to investigate the biological factors that contribute to initiation and maintenance of teen smoking and that pose barriers to success in smoking cessation; the goals of this research program include developing and evaluating treatments to promote adolescent smoking cessation. To accomplish these objectives, our program makes use of a unique infrastructure and highly interactive environment for mechanistic studies of teen smoking and smoking cessation at the levels of behavior, neural systems, and genetics. This study is sponsored by Philip Morris USA.