KIR3DL1 and preeclampsia: Accordingly, mothers being homozygous for KIR A haplotypes have a high risk of developing preeclampsia if the fetus carries one C2 allele, as KIR A homozygous individuals have two copies of the inhibiting KIR2DL2, which binds strongly to C2 (Hiby et al. 2004, 2010, 2014).