C9orf72 and amyotrophic lateral sclerosis: Moreover, leveraging transcriptomic data from ALS derived cell lines carrying a selection of pathogenic variants in genes that cause familial forms of ALS (C9orf72, SOD1, FUS and TARDBP) suggested that the action of B-Raf inhibitors may be of particular relevance to C9orf72 carriers, whilst the signal for B-vitamin signalling related targets was strongest in SOD1 carriers.