The most common (> 20% incidence) nonhematologic AEs reported with palbociclib–letrozole in the Japanese patients were stomatitis (53.1% vs 30.4% in the overall population, respectively), nasopharyngitis (43.8% vs 14.0%), nausea (28.1% vs 35.1%), alopecia (25.0% vs 32.9%), and increased alanine aminotransferase (21.9% vs 9.9%) (Table 4). This evidence concerns the gene GPT and alopecia.