PTEN-PI3K pathway. (A) Time course of PTEN after treating Daudi cells with 20-20, 22-20, and 20-22 at 10nM and rituximab at 133nM. The sample corresponding to 20-22 at 24 hours was lost during loading and thus not analyzed (†). (B) Daudi cells transfected with PTEN siRNA showed reduced expression of PTEN, compared with the untreated cells or cells transfected with control siRNA. (C) PTEN siRNA reduced the apoptosis of Daudi by 20-20, 22-20, and 20-22 at 10nM (P values with respect to *20-20, #22-20, and **20-22; P < .05). (D) The PI3K inhibitor, LY294002 (5μM), enhanced the apoptosis induced by 20-20, 22-20, and 20-22 at 10nM, but not rituximab at 133nM.