C9orf72 and frontotemporal dementia: Worms lacking a functional C9ORF72 orthologue ALFA‐1 show age‐dependent motor dysfunction, neurodegeneration of GABAergic motor neurons and sensitivity to osmotic stress, and when combined with TDP‐43 but not FUS transgene overexpression, the motor dysfunction became worse, thereby demonstrating a differential interaction between these ALS‐ and FTD‐associated genes [247].