We wondered whether placental ZNF554 down-regulation might have an epigenetic background, given that the ZNF554 flanking region contains several transposable elements, including several Alus, which are generally hypomethylated in germ cells and the placenta (260, 261), while their hypermethylation leading to altered gene expression may be detected in preeclampsia (262, 263). Here, ZNF554 is linked to preeclampsia.