The results show that doxorubicin and paclitaxel have greater ability to inhibit cell growth in MCF7 than MDAMB231 breast cancer cell lines (Figure 4D,E), and PFDN4 overexpression significantly inhibited the effect of doxorubicin and paclitaxel, but siRNA knockdown of PFDN4 expression enhanced the effect of doxorubicin and paclitaxel in cells (Figure 4F,G). The gene discussed is PFDN4; the disease is breast cancer.