KRAS and breast cancer: For example, compared with the orthotopic microenvironment, the subcutaneous microenvironment induces significant changes in the gene expression profile of human pancreatic cancer cells [33], chemosensitivity of murine colon carcinoma cells [34], invasive phenotype of ras‐transfected human bladder cancer cells [35], tumor growth of breast cancer patient‐derived xenografts [36], and tumor vasculature of human breast cancer xenografts and a mouse K‐ras‐induced lung cancer model [37, 38].