In the MONARCH2 trial, East Asian patients who were treated with fulvestrant plus abemaciclib had a higher incidence of neutropenia (all grade, 67.8% vs. 35.3%; grade ≥ 3, 44.5% vs. 17.6%) and ALT elevation (all grade, 23.3% vs. 8.5%; data not reported for grade ≥ 3) compared to non-East Asian ones [75]. The gene discussed is GPT; the disease is neutropenia.