Recent sequencing studies identified recurrent somatic gene mutations in CLL patients for proteins involved in DNA damage signaling and DNA repair, including mutations in TP53, ATM, CHEK1, CHEK2, POT1, BRCA1, and CHD2 (Puente et al., 2011; Quesada et al., 2011). Here, ATM is linked to B-cell chronic lymphocytic leukemia.