Figure 6(a) summarizes data pertaining to increased muscularization of pulmonary vessels in lung sections from hypoxic mice, while Figure 6(b) summarizes development of right ventricular hypertrophy measured in terms of the Fulton index (ratio of RV/LV + S weights). As expected, a male-dominant phenotype was observed in Wt hypoxic mice, but there was little sex bias in hypoxic SMC:BCL6+/− mice in terms of these indices of PAH (Figures 6(a) and 6(b)). Here, BCL6 is linked to pulmonary arterial hypertension.