NK cell cytotoxicity is reduced in the presence of dasatinib. CFSE-labeled NK cells were cultured at a 10:1 ratio with cell lines K562 (A) or Jurkat cell targets (B). After 3 hours incubation samples were stained with annexin V or 7AAD and analyzed on a flow cytometer; plots are representative of the percentage of each cell line staining positive for annexin V or 7AAD. A fixed number of beads were added to each sample to allow the total number of CFSE-negative target and CFSE-positive NK cells to be determined after flow analysis. From this the total number of viable K562s or Jurkat cells was determined (C) where nonviable cells were defined by annexin V positivity. Means and standard deviations are shown from at least 3 separate experiments using different healthy donors.