BCR and B-cell chronic lymphocytic leukemia: The main contributors to CLL pathogenesis are 1) antigenic B cell receptor (BCR) stimulation (microbial and autoantigens, neo-antigens created during apoptosis, autonomous signaling), 2) mutational status of the variable region of the immunoglobulin heavy (H) chain (IGHV) genes determining different response of malignant B cells to antigen stimulation, 3) involvement of different receptors in cell activation and interactions with the microenvironment, 4) genetic and epigenetic aberrations [1].