MUC5AC and chronic obstructive pulmonary disease: Wang et al. (2019) and others demonstrated that IL-1α and IL-1β expression in human bronchial epithelial cells (HBEC) were significantly upregulated in mucin protein Muc-5ac associated with high mucin secretion, and PIK-75 (PI3Kα specific inhibitor) significantly inhibited PM-induced inflammation and mucin hypersecretion in HBEC, while AS-252244 (PI3Kγ specific inhibitor) and IC-87114 did not. Small molecule inhibitors targeting the PI3K/Akt signaling pathway treat COPD through inhibiting oxidative stress and inflammation, as shown in Figure 2.