Previously identified smoking-related CpG sites that were also linked to smoky coal combustion – annotated to genes such as AHRR, SNORD93, NWD1, EDC3, STK24, ZDHHC14, HIF3A (Table S3) – converge on key pathways involved in pollutant response, respiratory diseases, and carcinogenesis. The gene discussed is AHRR; the disease is respiratory system disorder.