BCR and B-cell chronic lymphocytic leukemia: Notably, CLL patients carrying a specific stereotyped immunoglobulin gene in the subset 8 configuration (IGHV4-39/IGHD6-13/IGHJ5) are at a very high risk of RS development, and stereotyped subset 8 BCR configuration is highly enriched in DLBCL RS, supporting a role of BCR signaling in transformation [84].