China has the world's largest number of smokers and is the world's largest consumer of tobacco. 1 As of 2010, 28.1% of adults in China smoked, and 72.4% of non-smokers were exposed to second-hand smoke, according to the Global Adult Tobacco Survey. 2 Cigarette smoke contains a variety of harmful chemicals, including at least 70 carcinogens. 3 Long-term exposure to second-hand smoke is known to cause many diseases. Skin exposure to tobacco smoking has been found to be closely related to skin aging and the formation of pigmentation spots. 4 However, the mechanism by which cigarette smoke causes skin aging remains unclear.Ferroptosis is an iron-dependent form of regulated cell death driven by the accumulation of lipid peroxides to levels sufficient to trigger cell death. 5 Ferroptosis was recently linked to certain diseases, such as heart disease and lung fibrosis. 6,7 However, few studies have examined ferroptosis in skin-related diseases.This study analyzed ferroptosis in female skin exposed to cigarette smoke by downloading gene-set expression data from a public database, thus providing a new approach and theoretical basis for the treatment of skin aging and other skin diseases caused by exposure to cigarette smoke. | ME THODS | Data acquisitionThe gene expression dataset, GSE148221 (platform: GPL20844), 8 was downloaded from the Gene Expression Omnibus (https:// www.ncbi.nlm.nih.gov/geo/) database. 9 This dataset included 22