XBP1 and fetal growth restriction: Whilst spliced XBP1 mRNA levels and Xbp1s/t ratio (0.10 ± 0.03 vs 0.17±0.07; 0.02±0.005 vs 0.04 ±0.01, respectively, p<0.01, Fig 4A) were significantly decreased in liver samples of IUGR males, PERK and ASNS were expressed at higher levels in IUGR rats (0.02 ± 0.006 vs 0.014 ± 0.003; 0.006 ± 0.002 vs 0.003±0.001, respectively, p<0.05, Fig 4A).