Aggressive B-CLL. DR in poor prognosis.Down-regulation of TCL1 results the activation mTOR, NF- kB, Mdm2 and CyclinD1 pathways [178]. So its expression correlates with disease aggressiveness: high expression in aggressive B-CLL, and lower in indolent disease [48]. The gene discussed is MDM2; the disease is B-cell chronic lymphocytic leukemia.