Similar to the antigen-activated active BCR signaling in normal B cells chronic active BCR signaling, which typifies ABC-DLBCL, engages multiple downstream pathways, including PI3K/AKT/mTORC1 and canonical NF-κB signaling pathways [31, 96, 105, 106, 110, 124–131]. The gene discussed is PIK3CD; the disease is aneurysmal bone cyst.