Correlations between patient outcome and in vivo xenograft sensitivity to vincristine, dexamethasone, and methotrexate. Xenografts were stratified according to whether patients remain alive more than 4.5 years from diagnosis or died of their disease (Tables 1 and 5). GDF values for each drug are taken from Table 5. Each data point represents an individual xenograft, with the horizontal bar depicting the median of each subgroup. Xenografts derived from the good outcome subgroup were significantly more sensitive to vincristine (A) and dexamethasone (B), but not methotrexate (C), than poor outcome cases. In panel C, the relatively resistant xenograft in each subgroup is of T lineage. The sum of vincristine and dexamethasone GDF values provided a clearer separation between patient subgroups (D) than for vincristine (A) or dexamethasone (B) alone.