IFNG and breast cancer: Flow cytometry was used to determine cell surface expression of MHC II (versus mouse IgG2a κ isotype control, Fig. S1A) in unstained cells (data not shown), in three variants of MDA MB 435 human breast cancer cells, in HeLa cells, and in immortalized, but non-tumorigenic, epithelial breast MCF 10A cells in response to IFN-γ stimulation (Fig. 1A).