EZH2 and precursor B-cell acute lymphoblastic leukemia: In summary, histone modifications in B-ALL exhibit age-specific patterns: pediatric cases often display increased H3K36me2, reduced H4 acetylation, and EZH2-mediated repression, whereas adult cases more frequently exhibit KMT2A-driven H3K79 methylation and higher H4 acetylation, which is linked to a better prognosis.