ATF4 and preeclampsia: Our data support previous studies in which GRPs have been shown to be induced by hypoxic conditions.74, 75, 76 Severe hypoxia or anoxia has been shown to activate ATF4.77, 78 Of interest, both GRP78 and AFT4 protein levels have been shown to be up-regulated in the placentas of women with either early- or late-onset preeclampsia.79, 80, 81