The patient started the first-line treatment with six courses of FOLFIRINOX: oxaliplatin 85 mg/mq, irinotecan 180 mg/mq, leucovorin 400 mg/mq and fluorouracil 400 mg/mq given as a bolus followed by 2400 mg/mq as a 46 h continuous infusion,1q 14; the patient required a 20% dose reduction and prophylactic granulocyte colony stimulating factor (G-CSF) for grade 4 neutropenia. The gene discussed is CSF3; the disease is neutropenia.