Correlation between the serum IL-8 values and the number of CD34⁺ cells or CFU-GM on days 5 and 6 of G-CSF treatment. (A) Serum IL-8 levels versus the number of CD34⁺ cells per milliliter on day 5. (B) Serum IL-8 levels versus the number of CFU-GM per milliliter on day 5. (C) Serum IL-8 levels versus the number of CD34⁺ cells per milliliter on day 6. (D) Serum IL-8 levels versus the number of CFU-GM per milliliter on day 6. The serum IL-8 level correlated with the number of circulating CD34⁺ cells or CFU-GM.