Fig. 2From: Placental mitochondrial DNA and CYP1A1 gene methylation as molecular signatures for tobacco smoke exposure in pregnant women and the relevance for birth weightUnadjusted estimates of methylation levels in percentage (%) at four targeted CpG sites within the CYP1A1 promoter region of placental tissue. Estimated methylation levels at each CpG are indicated for each smoking category [black non-smokers (n = 255); grey past-smokers (n = 65); red smokers (n = 62)]. The error bars display the 95% confidence intervalsBack to article page