ZAP70 and B-cell chronic lymphocytic leukemia: Among these genes, ZAP70 encodes a kinase essential for thymopoiesis, T‐cell receptor‐dependent survival, and proliferation (Schim van der Loeff et al., 2014) and is aberrantly expressed in B‐cell malignancies, such as acute lymphoblastic leukemia and chronic lymphocytic leukemia (Rassenti et al., 2004).