The putative CLL precursor could be an antigen-experienced CD27+ B cell, expanded either in the course of a GC B-cell T-dependent or T-independent response by chronic antigen- stimulation through extrinsic or autoantigens. Over time, genetic abnormalities may accumulate in the genome of these chronically stimulated B cells and lead to the outgrow of clones with MBL phenotype. Additional genetic aberrations may be incorporated in the course of proliferation leading to the oncogenic hit that transform these precursor in bona fide CLL cells. .
