HOXA-AS2 and chronic obstructive pulmonary disease: The downregulation of HOXA cluster antisense RNA 2 (HOXA-AS2) is found in lung tissues from COPD patients and further studies in CSE-treated human pulmonary microvascular endothelial cells (HPMECs) demonstrated that the downregulation of HOXA-AS2 suppresses cell proliferation via Notch1 signaling (Zhou et al., 2020).