Pie charts illustrating the genetic heterogeneity and coexistence of distinct secondary genetic abnormalities in AML with t(8;21) and inv(16). The charts are based on patients with complete cytogenetic data and complete mutation status on KIT, FLT3, NRAS, and KRAS. (A) Genetic alterations in 141 AML patients with t(8;21) treated on AMLSG trials. Among the secondary chromosome aberrations, loss of a sex chromosome (−Y or −X), deletions of the long arm of chromosome 9 [del(9q)], and trisomy 8 (+8) are indicated; all other secondary chromosome aberrations constitute one group abbreviated in the chart as “o.c.a.” Due to the rounding error, all values do not add up to exactly 100%. (B) Genetic alterations in 166 AML patients with inv(16) treated on AMLSG trials. Among the secondary chromosome aberrations, trisomy 22 (+22) and trisomy 8 (+8) are indicated; all other secondary chromosome aberrations constitute one group abbreviated in the chart as o.c.a. Due to the rounding error, all values do not add up to exactly 100%. (Used with permission from Paschka et al.³²  Copyright American Society of Hematology.)