BCR and B-cell chronic lymphocytic leukemia: First, theauthors demonstrated that low-affinity BCR interactions with auto-antigens, such asphosphatidylcholine (PtC), are positively selected (Chen et al. 2013; Iacovelli et al. 2015); secondly, BCR signaling in response to suchantigens accelerated CLL development, indicating that BCR signaling triggered byexternal (auto)antigen increases the aggressiveness of the disease.