Granulocyte-colony stimulating factor (G-CSF) (administered subcutaneously at a fixed dose of 300 μg/day) was given to 45 patients (59.2%), particularly those with neutrophil counts <0.1 × 10(9)/L, severe clinical infectious features (e.g., collapse, septicemia, or extensive pneumonia), or renal failure. This evidence concerns the gene CSF3 and pneumonia.