Previous studies reported that PARP1 activation is required for primary neuron death elicited by peroxynitrite,[55] a DNA toxic agent triggering nitrosative stress in MS patients,[90] but it is dispensable for primary OL death induced by peroxynitrite.[91] These discrepant observations underscore a cell type‐dependent or context‐dependent role of PARP1 activation in cell death. The gene discussed is PARP1; the disease is myeloid sarcoma.