Known risk factors for anaphylactic reactions to anticancer drugs include age-related factors, concomitant diseases (e.g. chronic respiratory diseases), cardiovascular diseases, mastocytosis or clonal mast cell disorders, severe atopic disease, and some concomitant medications (e.g. β-adrenergic blockers and angiotensin-converting enzyme inhibitors).47 This evidence concerns the gene ACE and mastocytosis.