SLAMF1 and infection: At this time, both HSPCs (Lineage-, c-Kit+) and phenotypic long-term HSCs (Lineage- c-Kit+ CD135- CD150+ CD48) were depleted from the BM of WT mice during infection, but in Ifnar1-/- mice HSPCs were maintained and HSCs underwent a significant expansion as determined by both frequency and number (Fig 1C and 1D).