RT-PCR study of the expression of cyclin A1 in leukemia and preleukemia samples. (A) Dot plot show the level of expression of cyclin A1 in leukemia samples as a percentage of the level detected in the ML-1 myeloblast cell line. (B) Cyclin A1 mean levels of each group are shown. The statistical analysis of differences among the groups is discussed in the Results. (C) Ratio of cyclin A1/cyclin A is shown on a dot plot. Each dot represents one sample.