miRNAs increase CD69 surface expression on NK cells. (A) Highly purified (≥99%) human NK cells were treated with miRNAs, DOTAP vehicle control, or nonspecific, single-stranded RNA, RNA41 (RNA-Ctl),²⁴  for 36 hours in the presence of a low concentration of IL-12 (2.5 ng/mL). The treated cells were then subjected to flow cytometric analysis to determine the percentage of CD69⁺ cells. Representative data from 1 of 6 donors with similar results are shown. (B) Summary of data from 4 donors obtained in 1 experiment. *P < .05 and error bars represent standard deviation.