NCAM1 and acute promyelocytic leukemia: Furthermore, a statistically significant reduction in 5-year OS was observed in patients with CD15+ APL (58.8% vs. 83.2%, p = 0.016) and CD56+ APL (62.9% vs. 83.4%, p = 0.008), while the 5-year DFS was 90.2% (95% CI, 87.8–92.6) and 75.5% (95% CI, 71.9–79.1), respectively (Fig. 3).