First of all, the meta-analysis is based on case–control study, and there may have selection bias; second, the analysis of the relationship between miR-145 and specific clinicopathological characteristics of breast cancer, such as ER, PR, HER-2, lymph node metastasis and tumor size etc., due to the relatively small number of studies included, the results need to be further confirmed. This evidence concerns the gene ESR1 and breast cancer.