Status of patients before AZT treatment, response to treatment, and status of p53 gene and its transcriptional activity. The criteria for clinical therapeutic response were as follows: complete remission was defined as the disappearance of all measurable and assessable disease, lasting more than 3 months; partial remission was defined as reduction of leukemic cell count, lasting more than 1 month but less than 3 months; and not responding was defined as increase in leukemic cell count. CR indicates complete remission; PR, partial remission; NR, not responding; R, relapse; NA, not available; and ND, not determined.