ESR1 and neoplasm: Three rat strains (Charles River Laboratories, Germany) were used: 10- to 12-week-old healthy female Brown Norway (BN) rats, 8- to 11-week-old mild diabetic male Zucker diabetic fatty (ZDF) rats mild diabetic male Zucker diabetic fatty (ZDF) rats, and Rat1-myr-p110α and HBRX3077 patient-derived estrogen receptor (ER)–positive/PIK3CA-mutated tumor-bearing nude rats.