The positivity rates for ER, PR, HER2 expression, and Ki67 index in primary breast cancer were 63.6% (68/107), 58.9% (63/107), 19.8% (21/106), and 75.8% (75/99), respectively and for those in recurrent or metastatic lesions were 60.6% (65/107) (P = 0.672), 46.7% (50/107) (P = .013), 23.8% (25/105) (P = .482), and 83.5% (81/97) (P = .178), respectively. The gene discussed is ESR1; the disease is breast cancer.