Nicotine and Its Downstream Metabolites in Maternal and Cord Sera: Biomarkers of Prenatal Smoking Exposure Associated with Offspring DNA Methylation. - Kheirkhah Rahimabad P; Anthony TM; Jones AD; Eslamimehr S; Mukherjee N; Ewart S; Holloway JW; Arshad H; Commodore S; Karmaus W (International journal of environmental research and public health, 2020)