SMN2 and proximal spinal muscular atrophy: Previous studies in SMA animal models demonstrated that loss of the SMN protein leads to an activation of glia cells, such as astrocytes and microglia, and resulted in a higher expression of pro-inflammatory and pro-apoptotic cytokines such as TNFα, IL-1 and IL-6 as well as complement factors such as C1q and C35–11.