CYP1A1 and pulmonary arterial hypertension: Many of these weak inducers can suppress PAH-induced activation of CYP1A [11–16] by different mechanisms, for instance, competition for the active center of AhR [12], inhibition of phosphorylation of AhR and/or ARNT [17], or activation of transcriptional suppressors of CYP1A1 [4].