SERPINE1 and breast cancer: Biomarkers that may predict response to RT include:PAK6, which is involved in radiosensitivity;PLXND1 and SEMA7A, genes involved in cancer cell growth;and SERPINE1, an oncogene linked to drug resistance;S100A4 and TGFBI may also be potential biomarkers. Genes linked to the spread and outlook of breast cancer.