ESR1 and breast cancer: As shown in Table 2, we observed significant associations in breast cancer tissue specimens between positive resistin expression and several clinical parameters, including tumor size (P = 0.012), grade (P < 0.001), stage (P = 0.042), ER (P < 0.001) and PR (P < 0.001) status, HER2 status (P = 0.021), and molecular classification (P < 0.001).