CLL is usually described by many different prognostic factors, such as clinical staging systems (Rai and Binet), somatic hypermutation of the immunoglobulin heavy chain variable region (IgHV), surface CD38 expression, expression of zeta-associated protein 70 (ZAP-70), or chromosomal abnormalities (17p, 13q, 11q, and trisomy 12) [76]. The gene discussed is ZAP70; the disease is B-cell chronic lymphocytic leukemia.