P2RY12 and myeloid sarcoma: A possible scenario is that an increase uptake of P2X7R tracer that is accompanied by a decrease uptake of P2Y12R may indicate a progressing MS lesion, while upon immunomodulatory treatment if an increase of P2Y12R uptake is observed, this may indicate that the lesion is shifting to more anti-inflammatory environment and thus indicating a possible resolution of neuroinflammation and treatment efficiency.