HGF and autism: In the central nervous system, MET contributes to development of the cerebral cortex25,26 and cerebellum.25 Abnormal MET/HGF signaling in the cerebral cortex results in atypical interneuron migration from the ganglionic eminence and reduced interneurons in the frontal and parietal regions of cortex.28,29 In the cerebellum, aberrant signaling causes decreased proliferation of granule cells and reduction in the cerebellar size, particularly in the vermis.25 Both of these aberrations are consistent with those observed in brains of individuals with autism.26,27,60