Expression of UGT2A1, UGT2A2 and UGT2A3 isoform mRNA in human tissues. Quantitative real-time PCR was performed using reverse transcribed mRNA prepared from human fetal nasal mucosa (2 individuals), lung (2 individuals), and liver (2 individuals and 63 pooled donors) and also from adult lung (3 pooled donors), liver (47 pooled donors), and small intestine (5 pooled individuals). Results, mean ± SD of triplicate determinations, were normalized to 18S rRNA content.