Recurrent gains/amplifications havealso been commonly observed in lymphoid malignancies.For instance, amplification of BMI-1, a proto-oncogeneinvolved in regulation of proliferation and senescence(Jacobs et al., 1999), was reported to be associated withhigh BMI-1 expression in mantle cell lymphoma cases(Beaet al., 2001). The gene discussed is BMI1; the disease is mantle cell lymphoma.