HSC/HPC populations in physioxia vs ambient air groups. Cell numbers of (A) HSC/HPC (CD34+CD38−), (B) HSC (CD34+CD38−CD45RA−CD90+), and (C) multipotent progenitor (MPP, CD34+CD38−CD45RA−CD90−) were not different between physioxia and ambient air groups. D, Higher numbers of Lymphoid-primed multipotent progenitors (LMPP, CD34+CD38−CD45RA+CD90lo/−CD10−) and multi-lymphoid progenitors (MLP, CD34+CD38−CD45RA+CD90lo/−D10+) were observed in physioxia groups than in ambient air groups (P = .056) on day 7 (n = 3). E, Gene expression of the Notch1 signaling pathway (Notch1, HES1, DELTEX, TCF7, and GATA3) and PU.1 were not differently expressed between physioxia and ambient air groups at 48 hours (n = 4). Data are expressed as mean ± SEM. H, physioxia; HA, physioxia with AA; N, ambient air; NA, ambient air with AA; NS, not significant