Box plots of MTX AUC (A), MP AUC (B), and erythrocyte TGN level (C) in remission and relapse. AUCs and erythrocyte TGN level are the mean value for each patient. The box represents the 1st to 3rd quartile (the middle 50% of the data), the horizontal line is the median value, the bars represent the range, and the individual points are statistical outliers. On Rx, on therapy (see text for definition); BM, bone marrow.