(69) studied the expression of AGR2 in 155 cases of breast cancer samples at the mRNA and protein levels, and confirmed that there was a significant correlation between the expression of AGR2 and ER status, but they also found that the expression of AGR2 was positively correlated with low cell proliferation rate, low-grade tumors and negative lymph nodes, indicating that AGR2 was associated with good prognosis of breast cancer. Here, ESR1 is linked to breast cancer.