Ara-C survival curves for blasts from 4 patients recovered after cryopreservation. D10 values were measured for control cells and cells exposed to ATRA (10⁻⁷ mol/L) for 24 hours before drug administration.

(A) Patient UIN 1519 and (C) patient UIN 1375 had significant sensitization after ATRA; (B) patient UIN 1219 and (D) patient UIN 1456 had no ATRA effect. Curves are normalized to control values as 100%. (B and D) Survival cures were not significantly different; a single line has been drawn through values for control and ATRA-treated cells. Values used for normalization are (A) 220, 201; (B) 63, 55; (C) 90, 80; (D) 50, 31. Values for cells not exposed to ATRA are followed by values for cells exposed to ATRA.