MIRLET7D and pulmonary emphysema: miRNA expression-based studies have shown frequent downregulation of members of the Mirlet7 family, including Mirlet7a, Mirlet7b, Mirlet7c, Mirlet7d, Mirlet7e, and Mirlet7f in human emphysematous lung tissue and in murine models of emphysema, but the mechanism(s) of action remain ill-defined (Christenson et al., 2013; Pottelberge et al., 2011; Conickx et al., 2017; Izzotti et al., 2009).