Meggendorfer et al., Piazza et al., Pardanani et al., Elliott et al., Cui et al., and Gotlib found SETBP1 mutational frequencies of 14%19, 25%129, 33%76, 38%18, 42.9%126, and 56%121, respectively, in their series of CNL patients. The gene discussed is SETBP1; the disease is chronic neutrophilic leukemia.