TNBC, triple-negative breast cancer; ER, estrogen receptor; HER2, human epidermal growth factor 2; AI, aromatase inhibitor; DLT, dose-limiting toxicity; MTD, maximum tolerated dose; AE, adverse events; ORR, overall response rate; PFS, progression-free survival; mPFS, median PFS; OR, objective response; pCR, pathologic complete response; cCR, clinical complete response; OS, overall survival; NA, not applicable. The gene discussed is ESR1; the disease is triple-negative breast carcinoma.