CD154/IL4 stimulation increases CLL proliferation and induces TP53 expression. Top panel: Time course of Ki67 and TP53 expression in CD19+ CLL cells stimulated with rhCD154 and rhIL4. Bottom panel: Representative immunoblot of TP53 expression in CLL cells after 1, 3 and 7 days of co-culture with mouse L cells (NTL) or rhCD154 transfected-L Cells and rhIL4.