ETS1 p27 expression increases apoptosis in NK cells. (A) NK cells were sorted from d14 control and ETS1 p27 cultures. Quantitative polymerase chain reaction results are shown for the relative expression of indicated proapoptotic and antiapoptotic genes (mean ± SEM; n = 3-7). (B) NK cells from control and ETS1 p27 cultures were analyzed at d14 for apoptosis using annexin V and propidium iodide (PI) staining. The percentage annexin V and/or PI-positive cells in the NK cell gate is shown (mean ± SEM; n = 3-4). (C) Database for Annotation, Visualization and Integrated Discovery (DAVID) analysis of upregulated and downregulated genes of the RNA-sequencing analysis of ETS1 p27 vs control NK cells. The 10 most significant pathways are shown. (D) The number of upregulated and downregulated genes of ETS1 p27 vs control NK cells in the Gene Ontology positive and negative regulation of the mitotic cell cycle pathways. (E) Cell cycle analysis of d18 NK cells by 7-AAD/Ki67 staining. The percentage of cells at the indicated cell cycle phases is shown (n = 4). Significant difference compared with control, *P < .05 (Student t test). ATP, adenosine triphosphate; ctrl, control.