The genotype of patients may also be a predictor of treatment success: a recent randomized study came to the conclusion that people with aphasia with the typical val/val genotype of the brain-derived neurotrophic factor (BDNF) were more likely to benefit from anodal tDCS when compared to atypical BDNF-genotype (Met allele carriers) [61]. This evidence concerns the gene BDNF and Aphasia.