Yao Z, et al. – Aim was to reveal if concordant bone marrow involvement of diffuse large B–cell lymphoma (DLBCL) represented a distinct clinical and biological entity in the era of immunotherapy. In DLBCL with positive BM, results revealed clinical and biological heterogeneity. However, concordant BM involvement represented a distinct subset with unfavorable gene signatures, high–risk clinicopathologic features and poor prognosis.