HBP1 and Infertility: Notably, as the oocyte matures, the need for more energy requires a shift from glycolysis to OXPHOS.35 Thus, it is tempting to hypothesize that the effect on mitochondria and glycolysis through Hbp1 might be responsible for the major biological consequences on ovarian development and reserve, although it remains unclear in the study what causes its infertility in Hbp1−/− female.