CRYAB and myeloid sarcoma: Indeed, the small heat shock protein CRYAB, also named HSPB5, supports the reactive ASTR response that contributes to demyelination in the cerebellum of the cuprizone model [288] and is upregulated in active and chronic WM MS lesions, but not in GM MS lesions in both brain and spinal cord [289, 290] (Fig. 3).