KLRK1 and Zika virus infectious disease: Stimulation with culture supernatant from ZIKV-infected nondepleted PBMCs led to a significant upregulation in expression of CD107a, IFN-γ, and NKG2D in the CD94+ CD56+ NK cells (Fig. 6C), confirming the importance of monocytes in NK cell priming during ZIKV infection.