Fan X, et al. - Researchers evaluated the impact of metformin (a widely used anti-diabetic agent) in patients with diffuse large B-cell lymphoma (DLBCL) or follicular lymphoma grade 3b (FL3b) who achieved complete remission after the first-line treatment with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). For elderly and high-risk patients, metformin could be a safe and economic maintenance agent but it was not suitable for transplantation. The three independent unfavorable prognostic factors for OS were age>60, elevated serum LDH and diabetic patients without metformin maintenance; as seen in the multivariate analysis.