Inversely, cancer cells, when XRCC4 expression was knocked down, would feature increasing sensitivity to doxorubicin compared with these without XRCC4 knockdown [IC50s (95% CI), 0.22 (0.18-0.26) vs. 0.62 (0.58-0.67) μM] (Figure 5A and 5B). The gene discussed is XRCC4; the disease is cancer.