In the MONARCH3 trial, all grade neutropenia (57.8% vs. 37.3%) and ALT elevation (all grade, 32.4% vs. 10.7%; grade ≥ 3, 13.7% vs. 3.1%) was more frequently observed in East Asian, but there was no difference in neutropenia grade ≥ 3 (29.4% vs. 21.3%) and diarrhea (all grade, 88.2% vs. 79.6%). The gene discussed is GPT; the disease is neutropenia.