 This study investigated the effects of smoking cessation on epigenetic changes in humans. It found that smoking cessation results in decreased DNA methylation levels, which can be seen in body weight, expiration rate and tobacco-dependent scores. Additionally, bioinformatic analysis revealed that these changes are related to biological processes such as cell cycle regulation. This suggests that smoking cessation may lead to epigenetic changes that could potentially impact health outcomes. This article was authored by Jin Yu-sheng, Qin Ran-nai, Yan En-chi, and others.