The impact of MYCN gain on CLL prognosis was estimated by utilizing OS as a clinical endpoint. In the whole CLL cohort, after a median follow-up of 72.1 months for alive patients, 39/176 patients had died, accounting for a 5-years OS of 84.1%. By univariate analysis, CLL harboring MYCN gain at diagnosis were at increased risk of death (Events/N: 3/4; HR: 5.35; 95% CI 1.62-17.68; P 5 0.006; 6-years OS: 25.0%; 95% CI 0-67.5%) compared with CLL without MYCN gain (Events/N: 36/172; 6-year OS: 80.8%; 95% CI 74.0-87.6%) (Table III and Fig. 1) . Other features at diagnosis associated with CLL survival by univariate analysis were those expected in a consecutive CLL series and included IGHV homology 98% (P 5 0.005), 112 (P 5 0.049), 11q22-q23 deletion (P 5 0.014), 17p13 deletion (P < 0.001), TP53 mutations (P 5 0.048), CD38 expression (P 5 0.006), age >70 years (P < 0.001), Binet stage B-C (P < 0.001), and beta-2-microglobulin > 2.5 mg/l (P 5 0.001) (Table III) .