Surface expression of NK cell receptors upon CUR and RES treatment. PBMCs, pre-treated with CUR and/or RES at 5 µM for 48 h, were stained for NK cell activating receptors such as (A) NKG2D, DNAM-1, NKp46 and NKp30, (B) NK cell inhibitory receptors such as NKG2A and KIRs, and (C) NK cell exhaustion receptors such as PD-1 and TIGIT. Dots correspond to the mean of fluorescence (MFI) of the indicated receptors expressed on NK cells in PBMCs isolated from six healthy donors. Data are expressed as the mean ± SD bars. Statistical significance of the effects obtained with CUR and RES, alone or in combination, was calculated vs. those obtained in DMSO-treated cells with two-tailed unpaired Student’s t test (* p < 0.05, ** p < 0.01).