Quantitative PCR: RUNX3/ATRX ratio versus outcome. In children with de novo AML who harbor FLT3-MUs (n = 22), the ratio of RUNX3 to ATRX predicted outcome using quantitative RT-PCR from unamplified total RNA treated with DNAse I. A ratio more than 10 correlated with an EFS of 0%, a threshold ratio of 2 to 10 correlated with an EFS of 37%, and a ratio less than 2 correlated with an EFS of 62%. This same ratio in children with de novo AML and FTL3-WT did not correlate with outcome.