A decrease in total C9ORF72 mRNAs, and often also specifically of V2 and V1, was further reported in postmortem brain samples from C9-FTD/ALS patients, in particular in the frontal cortex and cerebellum (Belzil et al., 2013; Fratta et al., 2013; Waite et al., 2014; van Blitterswijk et al., 2015; Rizzu et al., 2016), as well as in the motor cortex and spinal cord (Donnelly et al., 2013). This evidence concerns the gene C9orf72 and frontotemporal dementia.