Environmental carcinogens, including PM2.5, cooking fumes, and radon, may induce somatic alterations such as EGFR mutations in exons 18–21 [19], gene rearrangements (e.g., ALK) [20], and gene fusions (e.g., RET) [21], and they interact with inherited susceptibility loci, including the 5p15.33 region [22], which is associated with lung cancer risk in never-smokers and implicates pathways involved in cell cycle control, DNA damage response, immune regulation, and genomic stability. The gene discussed is EGFR; the disease is lung cancer.