APP and breast cancer: We validated that MT/Shc313F/313F breast cancer cells uniformly and basally upregulated many IFNγ-responsive genes, including CXCL9 and components of the antigen processing and presentation (APP) machinery (Fig. 2c–e and Supplementary Fig. 5a–c) Finally, MT/Shc313F/313F breast cancer cells basally upregulated surface major histocompatibility complex (MHC) class I expression (Fig. 2f,g).