“…First, an increased prevalence of autoimmune diseases has been reported in FTLD patients compared to controls [45][46][47] and second, FTLD seems to be inversely linked to cancer [48], which may suggest alterations in the immune system or responses. Interestingly, the contribution of autoimmune mechanisms and genetic variation in loci associated with the immune system in FTLD were also suggested in recent studies [15,[49][50][51]. In line with these patient-derived data, C9orf72 repeat expansion has been linked to disturbances in the immune system [52], e.g., in mouse models with loss of function of the C9orf72 gene, which indicate a severe autoimmune phenotype, high mortality rate, and increased levels of proinflammatory cytokines and signs of neuroinflammation [16,17,52,53].…”