• G-CSF administration• Pneumocystis pneumonia and antiviral prophylaxis in severely neutropenic patients and those with prior CAR T-cell therapy• Consider antibacterial, antiviral, and antifungal prophylaxis in patients with prolonged neutropenia (ANC ≤500/μL for at least 7 days) or those at increased risk due to previous neutropenic complication or recurring episodes of neutropenic fever. The gene discussed is CSF3; the disease is Decreased total neutrophil count.