Updated publication reference for PubMed record(s): 26731301. Combustible cigarette smoking has major impact on human health. In order to reduce smoking-related health risk, the tobacco industry is developing modified risk tobacco products (MRTP). To assess the potential of such a prototype (pMRTP) to reduce health risk, we used C57BL/6 mice, model of chronic obstructive pulmonary disease (COPD), in a systems toxicology approach to investigate in a large, controlled study, classical toxicology end points in parallel to transcriptomics, lipidomics, and proteomics profiles in mice exposed to conventional cigarette smoke (3R4F) or a pMRTP aerosol for up to 7 months. We also included a cessation group and a switching-to-pMRTP group (after 2 months of 3R4F exposure), in addition to the control (fresh air exposed) group, to understand the potential benefit of switching to pMRTP for smokers who cannot or do not want to quit smoking. For quantitative proteomics analysis with the iTRAQ method, lung tissue samples from six mice (ie, six biological replicates) were analyzed for each exposure condition and time point (months 1, 3, 5, and 7 for 3R4F and pMRTP exposure and months 3, 5, and 7 for cessation and switch).