To address this, we examined the presence of messenger RNAs of arylhydrocarbon receptor (AhR), AhR nuclear translocator (Arnt) and two dioxin-responsive genes, cytochrome P-450 1B1 (CYP1B1) and downstream of tyrosine kinases (p62(dok)), in the endometrium of women with or without endometriosis using semi-quantitative reverse transcription-polymerase chain reaction.