BCR and B-cell chronic lymphocytic leukemia: The self-recognition for subset no. 4 BcR IGs is tight and long-lived, and the subset-specific SHMs stabilize the receptor structure, enhancing the half-life of the signalling complex (Table 2) as expected in an interaction leading to B-cell anergy31, 32, which is indeed a feature of the clinically indolent subset no. 4 CLL clones16, 33, 34.