CCND2 expression in ABC-DLBCL tumors, detected by RNA in situ hybridization, is closely related to the curative effect of R-CHOP and patient prognosis following R-CHOP treatment, and represents a potential biomarker for treatment efficacy and prognostic evaluation in patients with ABC-DLBCL. Here, CCND2 is linked to diffuse large B-cell lymphoma.