01A selectively blocks APRIL-induced protection in MM cells, alone and in cocultures with OCs, an effect that is further enhanced by lenalidomide or bortezomib. (A) U266 cells were incubated with APRIL or IL-6 in the presence or absence of lenalidomide, with or without 01A (10 μg/mL), and assayed by [3H]thymidine uptake at day 3. MM cell lines were cultured for 4 days in 2% fetal calf serum growth media with OCs in the presence of 01A with either (B) lenalidomide or (C) bortezomib. *P < .01.