CSF3 and diffuse large B-cell lymphoma: Primary prophylaxis with granulocyte colony-stimulating factor (G-CSF) in diffuse large B-cell lymphoma (DLBCL) patients undergoing rituximab-cyclophosphamide-doxorubicin-vincristine-prednisolone every 21 d (R-CHOP-21) chemotherapy varies based on physician discretion.