SMN2 and proximal spinal muscular atrophy: Overall, our qPCR experiments revealed that the primary metformin target Prkag3 matched its bioinformatics prediction of being downregulated in both Smn−/−;SMN2 and Smn2B/− SMA mice, suggesting that this gene may be involved in both severe and milder SMA pathologies and an appropriate therapeutic molecular target in SMA muscle.