PSMB8 and PSMB9 are two proteasome subunits, which belong to the immune-proteasome and are found specifically upregulated in adult OPCs, in areas of compromised remyelination, in people with longstanding multiple sclerosis, which is also coupled to inability of adult OPCs to differentiate into mature oligodendrocytes in an inflammatory demyelinating mouse model [28]. This evidence concerns the gene PSMB9 and multiple sclerosis.