IGF1 and chronic obstructive pulmonary disease: The other two lncRNAs, CASC2 and LOC729178, also act as miRNA sponges in COPD; their overexpression alleviated CSE-induced 16HBE cell inflammatory injury and apoptosis via the CASC2/miR-18a-5p/insuline-like growth factor I (IGF1) and LOC729178/miR-144-3p/PH domain leucine-rich repeat protein phosphatase 2 (PHLPP2) axes, respectively (Liu et al., 2021a; Wang et al., 2021b).