Correlation between CBS and SOD transcripts measured by RT-PCR in myeloblasts and in vitro drug activity and sensitivity. CBS transcripts correlated with both ³H-ara-CTP generation (Spearman correlation coefficient r = .666, P = .0003) and ara-C sensitivity (r = −.397, P = .003) (A and B, respectively). There were no significant correlations between SOD transcripts and ara-C (r = −.236, P = .07) or daunorubicin (r = −.217, P = .10) sensitivities (C and D, respectively). Transcript levels were normalized to 18S RNA transcript levels. (○) DS; (•) non-DS.