PROJECT SUMMARY Black cigarette smokers, 85% of whom smoke menthol cigarettes, suffer excess tobacco-caused morbidity and death, including cancer. Menthol (v. non-menthol) cigarette smokers, especially Black smokers, have a greater dependence on nicotine and are less likely to quit smoking, despite having more quit attempts. This may be partly due to greater abstinence-induced declines in positive mood/affect and nicotine cravings. However, there are limited data on the underlying mechanisms that explain smoking lapses among Black menthol smokers. Prior studies have used ecological momentary assessment (EMA) to examine how negative affect (i.e., poor mood), nicotine craving (i.e., urge to smoke), and contextual factors predict cigarette smoking lapse in real- time. Understanding these underlying mechanisms will help us develop effective cessation interventions for Black menthol smokers. To fill these critical research gaps, this study will use EMA to 1) examine the within- subject association between momentary negative affect, nicotine craving, and smoking lapse (aim 1) and 2) examine momentary perceived stress and discrimination as moderators of the momentary affect, nicotine craving, and smoking lapse relationship (aim 2) among Black menthol cigarette smokers who do and do not use e-cigarettes. Our central hypothesis is that, at the within-subjects level, higher levels of negative affect than usual will be associated with stronger nicotine cravings, and in turn predict momentary smoking lapse (any v. no smoking) among Black menthol cigarette smokers during a quit attempt. We will recruit 150 Black Arkansan menthol cigarette smokers aged 21-64 who plan to quit smoking in the next 30 days (n=100 cigarette only smokers; n=50 cigarette-e-cigarette dual users) to test our hypothesis on the primary outcome momentary of smoking lapse (any v no smoking). Secondary outcomes include time to smoking lapse, time to smoking relapse, and cigarette consumption. We will also conduct exploratory between-subject analyses by e-cigarette use status. Participants will complete a baseline 7-day pre-quit EMA wave and 7-day post-quit EMA wave, as well as baseline, 1 month, 3-month, and 6-month follow-up online surveys. Smoking status will be verified using exhaled carbon monoxide. This study will fill literary gaps on momentary predictors of smoking lapses among Black menthol smokers and will provide preliminary data for an R01 application. The PI has assembled an outstanding mentorship team who will guide her rigorous training and career development plans. Through formal coursework, summer institutes, hands-on training, and external trainings the PI will increase her competency in EMA/mHealth, randomized behavioral trials, advanced statistics, and tobacco disparities and regulatory science research. Receipt of this K award will strengthen the PI's likelihood of achieving her career goal to become an independent researcher and conduct technology-supported observationa...