To determine whether S100A14 ablation delays the development of metastasis in the mouse model, we crossed S100A14-null (S100A14-/-) mice with luminal B breast cancer model MMTV-PyMT (PyMT) mice to generate spontaneous breast tumors that lack S100A14 expression (S100A14-/- PyMT). Here, S100A14 is linked to breast cancer.