Using in situ hybridization histochemistry, this author reported decreased gene expression of B3GALT4 and ST3GAL2 in residual DAergic neurons in the SN in PD cases compared with the SN of age-matched controls [60], suggesting that dysfunctional ganglioside biosynthesis may result in decreased ganglioside levels. The gene discussed is B3GALT4; the disease is Parkinson disease.