SOX10 and myeloid sarcoma: MS lesions were identified using Luxol fast blue/MHCII staining (Fig. 5A) and classified as active, chronic active, chronic silent and shadow plaques.16,30 Interestingly, pS6RP+Sox10+ oligodendroglial cells were mainly detected in active lesions (Fig. 5A and B–D) and in rims of chronic active lesions (not shown) but were almost absent in chronic inactive lesions (Fig. 5E–G), in remyelinated lesions (Fig. 5H–J) and in the normal-appearing white matter from MS (Fig. 5K–M) and control cases.