NOTCH1 and B-cell chronic lymphocytic leukemia: Mutations of NOTCH1 can be observed in 2%–14% of patients with CLL and have been correlated with resistance of anti-CD20 monoclonal antibodies, treatment refractoriness, and disease transformation (Fabbri et al., 2011; Puente et al., 2011; Quesada et al., 2011; Rossi et al., 2012; Wang et al., 2011).