STAT4 and chronic obstructive pulmonary disease: Three kinds of extracts from herbs, namely, Pinellia pedatisecta Schott extract (PE) (Wang et al., 2021a), aqueous extract of Fritillariae cirrhosae (FC-AE) (Li et al., 2020b), and Euphorbia helioscopia L. aqueous extract (EAE) exhibited their excellent performance in alleviation of COPD and anti-cancer through inhibiting STAT4 signaling.