SMN2 and proximal spinal muscular atrophy: Here we analysed the protein levels of SMN and six biomarkers from the BforSMA biomarker panel (COMP [MIM: 600310], DPP4 [MIM: 102720], SPP1 [MIM: 166490], CLEC3B [MIM: 187520], VTN [MIM: 193190], and AHSG [MIM: 138680]) in plasma of severe and intermediate SMA mice.