KLRK1 and breast cancer: In the 3D BC cultures, the infiltration of NK cells into the spheroids, also previously reported in other models [49, 50], was enhanced following IFN-γ + TNF-α+treatment, and was associated with increased expression of activating receptors (NKG2D, DNAM-1, NKp30, and NKp46) on spheroid-infiltrating NK cells compared to non-infiltrating NK cells.