The cancer and leukemia Group B trial 9741 compared different sequential schedules of doxorubicin, cyclophosphamide, and paclitaxel given either every 3 weeks (conventional) or every 2 weeks (dose-dense) with systemic granulocyte colony-stimulating factor (G-CSF) support in the dose-dense arms. The gene discussed is CSF3; the disease is leukemia.