PLP1 and Parkinson disease: Notably, the expression analysis of myelin-related genes (Sox10, Plp1, Mbp, Mog, Mag, Mobp) across all 12 subclusters demonstrated significant downregulation in C2 and C10 (Figure 2H), confirming their association with functionally impaired oligodendrocyte states characterized by a deficient myelination capacity in PD.