In a recent study, PM2.5 exposure increased the production of MDA, myeloperoxidase, and ROS, along with an increased number of goblet cells in the bronchial epithelium as well as upregulated mucin 5 subtype AC via the Sestrin2/Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in an OVA-induced mouse asthma model [89]. The gene discussed is KEAP1; the disease is asthma.