Freije et al. (31) reported that the DEGs were Ccrn4lb, Per1, Per2, Per3, Nr1d1, Npas2, Arntl, Igfals, Nrep, Apol3, Got1, and so on in IUGR liver compared to AGA at 21 days of age. Here, NPAS2 is linked to fetal growth restriction.