NCR3 and Infertility: This difference in expression pattern makes eNK cells from infertile women positive for HHV-6A infection quite different from eNK cells commonly present in endometrial tissues (ref J Immunol, Figure 4), and from decidual NK cells, which express relatively high levels of NKp30, NKp44, and NKG2D (Hanna et al., 2006).