Table 2.

Phenotypes and function of human decidua NK cells in the first trimester, second trimester, and term trimester.

Frequency of dNK (%)	First trimester	Second trimester	Term trimester
CD56+ CD16−	95%	95%	85%
KIR2DL1	++	ND	+
KIR2DS1	+	ND	+/-
KIR2DL2/3	+++	ND	+
NKG2D	+	++	++
NKG2A	+++	+++	+++
NKp30	+++	+++	++
NKp46	+++	+++	+++
NKp80	+	++	++
NKp44	+	+	+
CD107a	++	+	+++
IFN-γ	++/+	++	+
TNF-α	+	ND	+

+/- < 10%;10% < + < 30%;30% < ++ < 60%; 60%>+++; ND (Not Detected).

[Key references (60, 68, 74–76)].