PTGS2 and lung adenocarcinoma: Although many studies had shown that berberine against lung adenocarcinoma mainly focused on different cell signaling pathways, including Sin3A/TOP2B (Chen et al., 2020), Bcl-2/Bax (Li et al., 2018), mTOR (Kumar et al., 2020) and NF-κB/COX-2, Akt/ERK (Lu et al., 2016), miR-19a/TF/MAPK (Chen et al., 2019), etc. It was not clear whether berberine could exert anticancer effect by interfering with DNA replication, the basic process of lung adenocarcinoma cell proliferation.