BCR-ABL mRNA levels progressively decline after CCR. Plotted are the median BCR-ABL mRNA levels (log-drop from a median baseline) at specific time points after first achieving CCR. The brackets show the interquartile range (25th-75th percentile levels). There was a significant time-dependent difference in BCR-ABL mRNA levels (P < .001) and a significant trend toward better responses with increasing times (trend P = .008). The cumulative percentage of patients achieving a major molecular response (MMR; 3 log-drop or greater) is also shown (Kaplan-Meier estimate). Samples drawn at or after the time of disease progression were excluded.