ESR1 and neoplasm: Future studies should meet the following criteria: first, baseline characteristics should be balanced among groups, including country, race, pathological types, stage, tumor size, lymph node status, number of patients, median age, and follow-up period, with HR and 95% CI data for progression or death, adjuvant therapy, previous sensitivity to endocrine therapy, estrogen-receptor and ECOG performance status, and metastatic site.