SEPTIN9 and B-cell chronic lymphocytic leukemia: These 22 B cell development-related DMRs are located in 16 genes, including genes involved in B cell-specific functionality, epigenetic remodeling, and carcinogenesis, such as TGFBR3, EHMT1, ACOX3, SEPTIN9, MYB, FAM174B, ARID3A, XXYLT1, and RHOBTB2. Although we observed ≥ 20% change in the methylation at the 22 of 67 DMRs between LP-CLL and IP-CLL among the SF3B1WT CLL samples, the difference was lost in SF3B1mut (Figure 4C).