Some common molecular and cytogenetic abnormities in CLL, such as tumor protein 53 (TP53) mutation, TP53 deletion, immunoglobulin heavy‐chain variable region (IGHV) mutations, and ATM deletion, are associated with clinical features and prognosis of patients with CLL 3, 4, 5, 6, 7, 8. This evidence concerns the gene ATM and B-cell chronic lymphocytic leukemia.