In vitro, Rituximab directly impact on cell viability of human CD20-expressing NH B-cell lymphoma cell lines by reducing (i) the expression of anti-apoptotic proteins Bcl-x, Bcl-2, XIAP, and Mcl-1 (138–140) and (ii) activity of kinases involved in BCR signaling (Lyn, Syk, Akt, Erk) (109, 141). This evidence concerns the gene BCL2L1 and B-cell non-Hodgkin lymphoma.