SMN1 and fibrosis: Consistent with previous studies in Lmna−/− and Myh6-Cre:Lmnaf/f mice [22,23], Lmnaflox/floxSM22αCre mice showed evidence of cardiac fibrosis and apoptosis, which was accompanied by elevated fibroblast and myofibroblast markers, including WGA staining and immunostaining of FSP-1 and SMA.