In addition, mouse models have evidenced the involvement of the Shh signaling pathway also in DS, since it has demonstrated that cerebral, skin, liver and intestine mice trisomic cells have a defective mitogenic Shh activity with cell proliferation impairment due to a higher expression of Ptch1, a receptor normally repressing the Shh pathway, located on Cr9 [34]. Here, SHH is linked to Dravet syndrome.