NK receptor phenotype analysis in MDS patients and healthy controls. (A) The percentage of NK cells that coexpressed NKp46, NKp30, and NKG2D was determined relative to isotype control antibody staining. Receptor expression was compared between group A versus normal and group B versus healthy controls (NL) using the Wilcoxon rank sum test. P values are shown only for those comparisons that were statistically significant. Horizontal lines represent the mean of that group. (B) Twenty-six MDS patients were divided into 2 equal groups based on the median expression of NKG2D and median expression of NKp30. The percent specific lysis of K562 at a 50:1 E/T ratio was then compared between groups with lower NKG2D plus lower NKp30 (n = 6), lower NKG2D plus higher NKp30 (n = 6), lower NKp30 plus higher NKG2D, and higher NKp30 plus higher NKG2D. Error bars indicate SD. These groups were compared using the Wilcoxon rank sum test.