Maternal cigarette smoking during pregnancy is associated with downregulation of miR-16, miR-21 and miR-146a. Quantitative RT-PCR analysis was used to examine the expression of the mature forms of miR-16 (A), miR-21 (B), miR-146a (C) and miR-182 (D), in primary placenta tissue samples from infants whose mothers smoked cigarettes (CS) during pregnancy (n = 8) and infants whose mothers did not smoke during pregnancy (No CS, n = 17). *indicates p < 0.01 and **indicates p < 0.0001 as determined by t-test.