CD16 characterization of decidual and peripheral NK cells. Freshly isolated peripheral and decidual lymphocytes were quadruple-stained as described in “Materials and methods.” NK cells were gated on the basis of the expression of CD56 and the lack of CD3 expression. Staining of decidual NK cells (A) and peripheral NK cells (B) is presented. The percentages of various populations, positive or negative, for CD16 expression are indicated. One representative staining is shown of 5 performed.