For instance, positron emission tomography (PET) using tracers that specifically label activated microglia and reactive astrocytes—such as second-generation tracers targeting the translocator protein (TSPO) or P2X7 receptors—in PET-MR multimodal scans could quantitatively assess the inhibitory impact on neuroinflammation in the brain and spinal cord of JIA patients (84). The gene discussed is P2RX7; the disease is juvenile idiopathic arthritis.