Demyelinating lesions in white and grey matter are the histopathological landmarks of MS, which are infiltrated by cells of the innate and adaptive immune system,114 whereas oligodendrocytes are responsible for the myelination process.131 PARP1, a newly associated protein for MS, is a driver for oligodendroglial development and myelination,132 and PARP1 inhibitors have been suggested as a potential therapy for MS,133 in line with our finding that elevated plasma PARP1 is associated with increased MS risk. The gene discussed is PARP1; the disease is myeloid sarcoma.