Single-cell analyses redefine cell heterogeneity signatures in diffuse large B-cell lymphoma and follicular lymphoma: Molecular insights and clinical impacts

B-cell non-Hodgkin's lymphoma (B-NHL) involves biologically and clinically heterogeneous lymphoid malignancies that arise from B cells in the lymphatic system. Understanding cell heterogeneity in B-NHL is of paramount importance for clinical diagnosis and treatment. In recent years, the rapid development of single-cell technologies has significantly improved B-NHL research in dissecting cell heterogeneity signatures at an unprecedented level. In this review, we aimed to characterize previously unrecognized cell subtypes, genetic and molecular diversity, and the dynamic interplay within the tumor microenvironment(TME) based on recent landmark single-cell studies in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL), the two most common and representative subtypes of B-NHL. In the meanwhile, we discuss the significant impact of these newly defined heterogeneity signatures on clinical practice, potentially informing better diagnostic tools and targeted treatments. Finally, we discuss how the continued advancement of single-cell technologies may further enhance our understanding of B-NHL pathogenesis.