Proposed models of genetic defect origin in mature lymphoid disease. The origin of mature lymphoid malignancies is disputed; this figure represents proposed models of evolution of the malignant clones. An increasing amount of evidence points to that at least some of the mature lymphoid malignancies (CLL, HCL, and TCL) carry genetic defects inherited from HSCs. Whether this is true for all lymphoid malignancies, or if some defects originate from mature B/T cells or CLPs, is not fully elucidated. MLP, multilymphoid progenitor.