Scientists at the NCI developed a research tool, a murine cell line model (JygMC(A)) with a reporter construct, of spontaneous metastatic mammary carcinoma that resembles the human breast cancer metastatic process in a triple negative mammary tumor. The assay is useful for screening compounds that specifically inhibit pathways involved in mammary carcinoma and can improve clinical management of of triple negative breast cancer that are greatly refractory to conventional chemo and radiotherapy. The key feature of the cell line is that when introduced orthotopically into the mammary gland of immunocompromised mice it produces murine mammary tumors that rapidly metastasize to distant sites, such as lungs, lymph nodes, liver and kidneys. This allows for precise tracking of tumor growth and metastasis.