MIRLET7A1 and pulmonary emphysema: In the present study, we established that the Mirlet7 family members encoded by the Mirlet7b/Mirlet7c2 and Mirlet7a1/Mirlet7f1/Mirlet7d clusters are downregulated in T cells from lungs of emphysema patients and emphysematous mice that were exposed to CS or nCB.