Association between MDR1/P-gp expression and CR achievement in B- and T-ALL.

CR rates among B-lineage (A) and T-lineage (B) ALL patients with negative (black bar) or positive (white bar) MDR1 expression. Ninety-seven of 126 MDR-negative B-ALL patients achieved CR compared with 19 of 32 MDR-positive patients; 28 of 31 MDR-negative T-ALL patients achieved CR compared with 4 of 11 MDR-positive patients.