In preterm infants, circulating CD34+ cell levels have been associated with various neonatal morbidities.40–44 Higher levels of hematopoietic stem cells have been reported in peripheral blood from preterm infants with brain injury42 and lung disease,40 and in cord blood hematopoietic stem cells have been associated with the development of several premature birth complications.13,45 However, the small sample size in our study precluded a meaningful analysis of associations between CD34+ cells and clinical outcomes. The gene discussed is CD34; the disease is lung disorder.