The underlying mechanism is not well understood but recently, it has been shown that the expression of the α1 subunit of sGC is downregulated by TGF-β in pulmonary artery smooth muscle cells via MEK and ERK signaling (Du and Roberts, 2019) and IL-1β in perinatal lung fibroblasts via TAK1 and NF-κB signaling (Zhong et al., 2020) and both inflammatory mediators are increased in COPD and asthma disease so they might be also involved on the reduction of α1 subunit of sGC in the epithelial cells of these patients. The gene discussed is TGFB1; the disease is chronic obstructive pulmonary disease.