SOX10 and myeloid sarcoma: Quantification of the percentage Sox10+pS6RP+ cells over the total number of Sox10+ oligodendroglia in different MS lesion types revealed a peak of expression in active lesions, as compared with chronic silent lesions, shadow plaques and normal-appearing white matter (Fig. 5N), suggesting that pS6RP labelled a transient stage of the oligodendroglial lineage cells in human.