Multi-hit mutation modeling. (a) CMML incidence rate in the United States and Canada (2005–2011, CINA). (b) Multi-hit mutation modeling under a constant accrual model compared with observed CMML incidence rate. (c) Total CMML mutations versus age at diagnosis (N = 35 having biopsy and diagnosis within 1 year, similar results not shown if within 1 month). Single outlier (only patient recorded with SM-CMML diagnosed at age 36 years) with no mutations not shown. (d) Variant allele frequencies by gene and sample (N = 69). Black, nonsense mutation; red, frameshift indel; blue, nonsynonymous mutation; purple, splice-site mutation; orange, nonframeshift indel.