ACTA1 and pulmonary emphysema: To determine the effects of Hhip haploinsufficiency on ASMCs function in vivo, we performed α-SMA immunofluorescence (IF) staining in lung sections from unchallenged Hhip+/- and Hhip+/+ mice at 8 months of age preceding spontaneous emphysema development in Hhip+/- mice at 10 months of age21.