SLC17A6 and Hand-foot syndrome: As VGLUT2 is the only VGLUT expressed by STN glutamatergic projections to the SNr [71], this confirms our hypothesis that information transmission via the transsubthalamic pathway is not completely blocked during STN-HFS [15,16,31,32,67,68] although the effect on VGLUT2 expression in the SNr might also be mediated by the modulation of thalamic afferents during STN-HFS.