‐use supportive measures (i.e., G‐CSF in primary prophylaxis, treatment of underlying anemia, prevention of mucositis);‐avoid using cytotoxic chemotherapy if risk of toxicity is higher than 40% and not preventable (i.e., by using prophylactic G‐CSF)‐review and reconcile polypharmacy‐If cytotoxic chemotherapy is highly indicated, use regimens with lower predicted toxicity if possible. Here, CSF3 is linked to anemia (phenotype).