In a study of two independent post-mortem cohorts, we recently showed that the ratio of myelin-associated glycoprotein (MAG) to proteolipid protein 1 (PLP1) in the white matter correlated inversely with the severity of small vessel disease, and so presumably with the degree of ante-mortem ischemia (Barker et al., 2013). Here, PLP1 is linked to ischemia.