To further verify the relationship between PTPN1 and drug sensitivity in cancer cells, we performed the CCK-8 viability assay on breast cancer cell lines using various concentrations (0, 5, 10, 15, 20, 25, and 30 μM) of the chemotherapeutic drug, paclitaxel, which is widely used in breast cancer chemotherapy. This evidence concerns the gene PTPN1 and breast cancer.