Even though the patient was on continuous granulocyte colony stimulating factor (G-CSF) therapy (48 million IU/every other day) leukopenia prevailed (leukocytes 0.93/nl, neutrophils 0.76/nl, hemoglobin 10.0 g/dl, thrombocytes 125/nl). This evidence concerns the gene CSF3 and Decreased total leukocyte count.