Kreitzberg DS, et al. - A total of 5,478 participants who were students from 24 2-year and 4-year Texas colleges were enrolled in this study by the experts in order investigate bidirectional correlations between self-reported exposure to electronic nicotine delivery system (ENDS) marketing and ENDS use, over four 6-month follow-up surveys, among young adults. Nearly 64% (n = 3,506) and 64% of the cohort were non-white and were female, respectively, and the average age was 20 years. Self-reported exposure to ENDS marketing at each prior wave prognosticated ENDS use at each subsequent wave. At waves 3 and 4, respectively, ENDS use at waves 2 and 3 prognosticated self-reported exposure to ENDS marketing. However, ENDS users were more inclined vs non-users to report exposure to ENDS marketing, self-reported exposure to ENDS marketing prognosticated succeeding ENDS use controlling for prior ENDS use. Thus, among young adult college students in Texas, USA, self-reported exposure to ENDS marketing was bi-directionally correlated with past 30-day use of ENDS from 2014/15 to 2016.