CD40LG and B-cell chronic lymphocytic leukemia: High-throughput protein profiling showed that co-culture with GFP-APRIL + CD40L fibroblasts for 24 h significantly induced CLL signaling in several pathways related to cell proliferation, including AKT (pS473), mTOR (pS2448), NF-κB p65 (pS529), and p38 MAPK (pT180/Y182) (Fig. 1f, g).