Relation of the serum EPO to Hb levels in patients with leukemia studied at time of diagnosis, n = 55 (A) or during intensive chemotherapy (CT), n = 29 (B) and in patients with solid tumor at diagnosis, n = 56 (C), or during intensive CT, n = 31 (D). Solid lines represent the regression lines computed in each group of patients. Dashed lines depict the regression line and the 95% confidence limits of the control group. In graph (D), solid triangles represent patients receiving cisplatin (n = 6).