Hypothetical models of SOX11-possitive vs SOX11-negative MCL. The naive B cell carrying the t(11;14) colonizes the mantle zone of the lymphoid follicle and generates an in situ MCL lesion. Most MCLs evolve from these cells in the marginal zone with no or limited IGHV somatic mutations and SOX11 expression. SOX11 overexpression in conventional MCL may block the cells in a mature B-cell stage, preventing their further differentiation thought the SOX11-PAX5-PRDM1/BLIMP regulatory axis. Alternatively, some cells with the t(11;14) may enter the germinal center, undergo IGHV somatic hypermutation, and lack expression of SOX11. SOX11 may modulate the mature B-cell and early plasma cell differentiation program in MCL.