CCL3 and myeloproliferative disorder: For instance, activating-mutations in Nestin+ MSCs of the protein tyrosine phosphatase SHP2 (a positive regulator of the RAS signaling pathway) can lead to the development of childhood-like MPN by hyperactivating HSCs via overproduction of the CC-chemokine CCL3 and IL-1β (Dong et al., 2016).