CD19 and B-cell non-Hodgkin lymphoma: Comparatively, Cd19-Cre driven expression of a mutant Ezh2 protein under the control of the endogenous promoter induced B-cell lymphomas at high penetrance, but the phenotype of these tumors (B220+, CD19+, IgM+, CD43+, CD5+ and Mac1+) is not reminiscent of the human lymphomas, reinforcing the importance of achieving precise temporal and spatial control of the target genetic lesions (119).