As previous studies have revealed that estrogens may regulate the focal adhesion complexes not only through the classical estrogen receptor α (ERα) in breast tumor and endothelial cells [54–56] but also via GPER in human dermal fibroblasts [57], we aimed to investigate whether GPER is involved in the activation of FAK in TNBC MDA-MB 231 and SUM159 cells [58]. This evidence concerns the gene ESR1 and breast neoplasm.