An interesting finding regarding the 10 most strongly downregulated genes in NAWM of MS patients with high cortisol was the presence of the purinergic receptor P2RY12 (Fig. 3b), a microglia signature gene shown to play a major role in microglial activation, synaptic plasticity, and closure of the injured blood-brain barrier [8, 52, 76]. Here, P2RY12 is linked to myeloid sarcoma.