Primary miR-181ab-1 and miR-181ab-2 levels change in response to immune regulatory cytokines. Blood NK cells were cultured overnight in the presence of media alone (Nil) or the indicated stimulants. Avg and SEMs of 3 donors are presented. A. Cq values were corrected with those of 18S rRNA. Statistical significance is indicated: pri-miR-181ab-1 and -2 differ under the indicated conditions (*, p < 0.05; †, p < 0.01); the pri-miR level differs between media alone and the indicated stimulation (‡, p < 0.05; §, p < 0.01). Compared to media alone, the ratio of pri-miR-181ab-1 vs -2 was significantly different for all stimulations (IL-12/IL-18, p < 0.05; all others, p < 0.01). For graphic presentation, corrected Cq values were converted to numerical values and normalized to the level of pri-miR-181ab-1 (Nil). B. miRNA levels were assessed by RT-qPCR and were normalized to RNU-24 and to the unstimulated controls.