In line with this assumption, TNF-α strongly induces CX3CL1 expression in human first trimester placenta, and has been suggested as one of the underlying triggers of upregulated CX3CL1 in severe early-onset pre-eclampsia (PE), which is a pathology that is a major contributor to maternal and neonatal morbidity [18,27]. Here, CX3CL1 is linked to preeclampsia.