Using eclosion as a readout, we performed a genome-wide genetic screen to identify modifiers of FUS-ALS in vivo, and found that microtubule star (mts) (the Drosophila ortholog of PPP2CA) and shaggy (sgg) (the Drosophila ortholog of GSK3B), are novel modifiers of FUS-associated ALS. This evidence concerns the gene FUS and amyotrophic lateral sclerosis.