Both HO-1 and CO displayed anti-inflammatory, antioxidative stress, and immune regulation properties in an asthma animal model [8,9] and inhibited the proliferation of cultured human airway smooth muscle cells (HASMCs) through downregulation of ERK1/2 activation, which indicated the anti-airway remodeling effects of HO-1. The gene discussed is HMOX1; the disease is asthma.