MNX1 and amyotrophic lateral sclerosis: Mouse GFP-Hb9+ motor neurons were plated onto LV-SRSF1-RNAi transduced astrocytes derived from three controls and three C9ORF72-ALS patient fibroblast lines (Table 1) and automatically counted daily for three days using a high-throughput imaging system (Supplementary Fig. 2b, Methods).