Updated project metadata. Aiming to reduce smoking-related health risks, potential reduced risk products (pRRPs) are being developed. The Tobacco Heating System (THS) 2.2 is a recently developed pRRP, which utilizes the heat-not-burn principle. In this study, systems toxicology approaches were engaged to assess the respiratory effects of a mentholated version of THS2.2 (THS2.2M) in a 90-day rat inhalation study (OECD test guideline 413). This is the quantitative proteomics data set for rat lung tissue. As described in the sample processing protocol, two different iTRAQ sets were defined and analyzed separately. See i_Rat-THS2.2M-TG413_protItraq_LeftLung.xlsx for sample annotations and file mappings.