CXCR4 and infection: As shown in Table3, in newborns who developed IVH, RDS, infection, anemia, or any of the seven analyzed prematurity complications (in this subgroup, distinguished for statistical purposes, we grouped together preterm infants with at least one of the seven analyzed complications: IVH, RDS, BPD, ROP, NEC, infection, anemia) a significantly lower number of circulating CD45+lin-CD184+ cells was observed in comparison to infants without these complications.