HIF1A and persistent fetal circulation syndrome: 2004). Hek‐II is an isoform of hexokinase that phosphorylates hexoses (e.g., glucose to glucose‐6‐phosphate) aerobically to produce ATP. We previously reported that there is a decrease in ATP generation in PPHN‐PAEC, compared to control PAEC (Afolayan et al. 2016). We observed a HIF‐1α–dependent increase in the levels of Hek‐II in PPHN‐PAEC in this study.