Cytokine-induced lytic granule convergence does not occur through canonical signaling but depends on Src kinase activity. Time-lapse frames of lytic granule movement in YTS GFP-tubulin cells stimulated with IL-2 after (A) DMSO, (B) ZM449829, or (C) PP2 treatment. In each image, confocal immunofluorescence in the plane of the MTOC is shown. Green, GFP-tubulin; red, LysoTracker-loaded acidified organelles. Cells were imaged for 2 to 4 minutes before IL-2 was added. Time = 0 minutes represents the time at which IL-2 was added. (D) Quantitative analyses of lytic granule distance from the MTOC as a function of time as measured by mean MTOC to granule distance in 5 to 10 cells per condition; error bars show ±SD. Mean distance of lytic granules from the MTOC after IL-2 addition was not significantly different in ZM449829-treated NK cells compared with DMSO-treated NK cells but was significantly greater in PP2-treated NK cells (***P < .001). Mean distance of lytic granules from the MTOC after IL-10 addition was also significantly greater than after IL-2 addition (**P < .01).