Epigenetic regulation is critical to B cell development, guiding gene expression via DNA methylation, histone modifications, chromatin remodeling, and noncoding RNAs. In mature B cell neoplasms, particularly diffuse large B cell lymphoma (DLBCL), follicular lymphoma (FL), and chronic lymphocytic leukemia (CLL), these mechanisms are frequently disrupted. Recurrent mutations in key epigenetic regulators such as EZH2, KMT2D, CREBBP, and TET2 lead to altered chromatin states, repression of tumor suppressor genes, and enhanced oncogenic signaling. Dysregulation of specific microRNAs (e.g., miR-155, miR-21) further contributes to pathogenesis and therapeutic resistance. In DLBCL, hypermethylation of SMAD1 and CREBBP mutations are associated with immune evasion and chemoresistance. In FL, EZH2 gain-of-function and KMT2D loss-of-function mutations alter germinal center B cell programming, while in CLL, DNA hypomethylation patterns reflect the cell of origin and correlate with clinical outcome. Targeted therapies such as the EZH2 inhibitor tazemetostat have demonstrated efficacy in EZH2-mutant FL, while HDAC and BET inhibitors show variable responses across B cell malignancies. The limitations of current epigenetic therapies reflect the complexity of targeting epigenetic dysregulation rather than therapeutic futility. These challenges nonetheless highlight the relevance of epigenetic alterations as biomarkers and therapeutic targets, with potential to improve the management of mature B cell neoplasms.

Chronic lymphocytic leukemia (CLL), the most common type of leukemia in adults, is characterized by a high degree of clinical heterogeneity that is influenced by the disease’s molecular complexity. The genes most frequently affected in CLL cluster into specific biological pathways, including B-cell receptor (BCR) signaling, apoptosis, NF-κB, and NOTCH1 signaling. BCR signaling and the apoptosis pathway have been exploited to design targeted medicines for CLL therapy. Consistently, molecules that selectively inhibit specific BCR components, namely Bruton tyrosine kinase (BTK) and phosphoinositide 3-kinase (PI3K) as well as inhibitors of BCL2, have revolutionized the therapeutic management of CLL patients. Several BTK inhibitors and PI3K inhibitors with different modes of action are currently used or are in development in advanced stage clinical trials. Moreover, the restoration of apoptosis by the BCL2 inhibitor venetoclax offers meaningful clinical activity with a fixed-duration scheme. Inhibitors of the BCR and of BCL2 are able to overcome the chemorefractoriness associated with high-risk genetic features, including TP53 disruption. Other signaling cascades involved in CLL pathogenesis, in particular NOTCH signaling and NF-kB signaling, already provide biomarkers for a precision medicine approach to CLL and may represent potential druggable targets for the future. The aim of the present review is to discuss the druggable pathways of CLL and to provide the biological background of the high efficacy of targeted biological drugs in CLL.

Despite the development of robust prognostic biomarkers for risk stratification in newly diagnosed diffuse large B-cell lymphoma (DLBCL), namely international prognostic index (IPI), cell-of-origin (COO), circulating tumor DNA (ctDNA) and molecular clusters, none of these capture potential host-related features. In this study, untargeted plasma metabolomics was performed in a discovery cohort of 96 newly diagnosed R-CHOP-treated DLBCL patients. The key finding was validated in an independent cohort of 42 DLBCL with comparable clinical characteristics and outcomes. None of the 280 identified plasma metabolites was associated with COO classification subtypes. Conversely, the metabolomic profile appeared to show variations across ctDNA-defined molecular clusters. After an elastic net regression-based survival analysis, 2-hydroxybutyric acid (2HB) was selected as the only endogenous metabolite to be associated with worse progression-free survival (PFS) in the discovery cohort. The impact of 2HB levels on PFS was confirmed in the validation cohort. Also, 2HB levels (HR 2.09, 95% CI 1.04-4.19, p=0.04) maintained an independent association with shorter PFS when adjusted for higher ctDNA levels (HR 2.08, 95% CI 1.06-4.08, p=0.03). Therefore, 2HB and ctDNA levels were included in a two-factor prognostic score based entirely on minimally invasive plasma-derived biomarkers. This hypothesis-generating score improved outcome prediction compared with ctDNA assessment alone and enabled the identification of high-risk patients who might benefit from early restaging and potential treatment intensification (24-month PFS 28.8%). In conclusion, plasma metabolomics revealed a prognostically relevant role and 2HB sorted out as a potential host-related biomarker able to refine risk stratification in newly diagnosed DLBCL.