Our data revealed that PAH (0.25, 0.5 and 1 μM) decreased the expression of p65, p50, IKKα and IKKβ in RAW264.7 cells dose-dependently (Figure 6b), illustrating that PAH significantly inhibited RANKL-induced NF-κB activation via suppression of IKK. Here, NFKB1 is linked to pulmonary arterial hypertension.