However, since the Lhx2−/− embryos start to die in utero even prior to initiation of HF morphogenesis, we confirmed these observations in a mouse strain harbouring a hypomorphic allele of Lhx2 (Lhx2Neo) where HF development can be followed to a gestational age when pelage HF morphogenesis is firmly established. The gene discussed is LHX2; the disease is hydrops fetalis.