One of the largest studies to date reported GPER expression in 84 normal breast tissues and 781 primary breast tumours using TCGA RNAseq data accessed through the UCSC Cancer Genomics Browser; they demonstrated that GPER expression is lower in primary tumours than normal breast tissues and that higher GPER expression in breast cancer patients was associated with increased survival, which is in agreement with our findings [19]. This evidence concerns the gene GPER1 and breast cancer.