Flow cytometry analysis of decidual leukocytes. Comparison of typical subset-markers of NK cells (CD3-, CD56+, CD16+/-) and the non-typical dNK cells marker (CD9+). A-D) Representative FACS for two-color staining for decidual leukocytes. E-G) Representative FACS for three-color staining for decidual leukocytes. H-K) Representative FACS two-color staining for peripheral blood mononuclear cells (PBMC). L-M) Representative FACS three-color staining for PBMC. A, E, H, L) negative cells; B, I) upper left quadrants (UL): CD56+ CD3- cells; C, J) UL: CD56+ CD16- cells; upper right quadrants (UR): CD56+ CD16+ cells; D, K) UR: CD56+CD9+ cells. F, M) R1 and R2, gate for CD3- cells; G, N) CD56+CD9+/- expression on CD3- cells.