Fig. 1.
Dose-response curves of MTX in absence or presence of 25 μmol/L Hx, 10 μmol/L TdR, or 1 × 106/mL lysed primary ALL cells for (A) HL60 and (B) U937. The results are expressed as mean values of three experiments ± SD. Protection from the MTX-induced growth inhibition was most obvious when Hx and TdR were added together.