IL2 and breast cancer: To test whether resistance to apoptosis as well as downregulation of NK cell ligands by miR-519a-3p results in lower NK cell-mediated lysis of breast cancer cells, we co-cultured 51Cr-loaded MCF10A, MDA-MB-468 and HCC1143 cells with IL-2-activated NK cells and then analyzed 51Cr release as a measure for tumor cell killing by NK cells.