Recognizing the prognostic significance of CD37, Xu-Monette et al. proposed two refined risk stratification models for DLBCL: the molecularly adjusted IPI for R-CHOP (M-IPI-R), which incorporates CD37 negativity and the ABC subtype with the IPI; and IPI + IHC, which integrates immunohistochemical (IHC) expression of CD37, Myc, and Bcl-2 with IPI. Here, CD37 is linked to diffuse large B-cell lymphoma.