CCND1 overexpression was not sufficient to induce doxorubicin resistance in CCND1-neutral breast cancer cell lines, nor did CCND1 knock-down increase doxorubicin sensitivity in CCDN1-amplified cell lines, suggesting that CCND1 is not the sole driver of doxorubicine resistance in this setting. The gene discussed is CCND1; the disease is breast carcinoma.