The major guidelines recommend primary G-CSF prophylaxis for patients with a high FN risk (≥20%) receiving chemotherapy and patients classified as intermediate risk (10%–19%) with risk factors of FN, such as older age, bone marrow invasion, poor PS, malnutrition, etc.[16,19,20] The FN incidence in patients with DLBCL receiving R-CHOP is reportedly 18% to 19%, which is considered to be intermediate-risk.[20] Therefore, administration of pegfilgrastim as primary prophylaxis is recommended from the first R-CHOP cycle in patients with risk factors of FN. This evidence concerns the gene CSF3 and diffuse large B-cell lymphoma.