en عمومى General نامه به سردبیر Letter to Editor <span style="line-height:2;"><span style="font-size:16px;"><span style="font-family:Times New Roman;">Although the genome has been a cornerstone of medical research, it alone cannot describe the complex etiology of the majority of chronic diseases. The prime role of environmental exposures and lifestyle has hence introduced the concept of the exposome. The term exposome, coined by Christopher Wild, represents the totality of environmental exposures from conception onward and is considered a complement to the genome. ^{[1, 2]} Advancing exposome research offers the extraordinary opportunity for integration of exposure science, analytical chemistry, biomedicine, and toxicology within translational healthcare.<br> Wild&#39;s definition posited three overlapping domains: the general external environment, which includes elements such as urban/rural surroundings and climate; the specific external environment, which includes elements such as pollutants, diet, and occupation; and the internal environment, which includes metabolism, oxidative stress, and the microbiome. ^{[3, 4]} This has been further elaborated to include the behavioral factors and endogenous responses, placing environmental exposures as equivalent to genomics in determining health. ^{[5, 6]} Examples of these include air pollution and cardiovascular disease ^[7], maternal smoking and neonatal epigenetic changes ^[8], and the gut microbiome in intervening on diet and immune function. ^[9] Characterization of the exposome is both a major challenge and a tall opportunity for public health.<br> Characterization of the exposome necessitates a structured approach conceptualized into three phases: (1) analytical identification and measurement, (2) computational data processing, and (3) integrative understanding of exposure-effect interplay. Thousands of agents are present across biological matrices in the exposome with significant temporal variability. ^[10] Longitudinal cohort studies, such as EXPOsOMICS ^[3], HELIX ^[11], and CHEAR ^[12], are pioneering systematic approaches to capture such data. </span></span></span> 405 408 http://ijrabms.umsu.ac.ir/browse.php?a_code=A-10-601-1&slc_lang=en&sid=1 Abbas Jafari jafari.ab@umsu.ac.ir 10031947532846005549 10031947532846005549 No Cellular and Molecular Research Center, Cellular and Molecular Medicine Research Institute, Urmia University of Medical Sciences, Urmia, Iran Behrouz Seyfinejad seyfinejad.b@umsu.ac.ir 10031947532846005550 10031947532846005550 Yes Cellular and Molecular Research Center, Cellular and Molecular Medicine Research Institute, Urmia University of Medical Sciences, Urmia, Iran