TACR1 and cancer: The international guidelines established by the American Society of Clinical Oncology, Multinational Association of Supportive Care in Cancer, and the European Society of Medical Oncology have recommended a combination of olanzapine 10 mg with 5-hydroxytryptamine type 3 receptor antagonists (5-HT3 RA), neurokinin-1 receptor antagonists (NK1 RA), and dexamethasone against CINV in cancer patients receiving highly emetogenic chemotherapy, while olanzapine 5-10 mg was suggested in National Comprehensive Cancer Network guideline [12–14].