Finally, the investigation of phenotypes associated with the repeat expension r(GGGGCC)exp in C9orf72 that leads to frontotemporal dementia (FTD) and ALS resulted in the detection of cytoplasmic poly(GP) as well as poly(PR) inclusions in iNs but not in fibroblasts (Su et al., 2014). Here, C9orf72 is linked to frontotemporal dementia.