PGK1 and primary progressive multiple sclerosis: In case of OPCs treated with CSF from PPMS patients, we found that most of the glycolytic genes, including Hk1, Gpi, Gapdh, Tpi, Pgk1, Eno2, Pk, and Pkm2, were reduced in gene expression (Figures 2A,B,D–F,I–K).