Regardless, additional validation of tumor/stromal Cav-1 in breast cancer patients as a predictive biomarker for nab-paclitaxel therapy is warranted, and tumor/stromal Cav-1 of metastatic sites through re-biopsy may better reflect the efficacy of nab-paclitaxel in metastatic breast cancer patients. The gene discussed is CAV1; the disease is breast cancer.