In particular, integrin-linked kinase (ILK) [164], ER regulator PELP-1 protein [167,170], and the formation of a multiprotein complex between ERα, Src, PI3K, and the actin-regulator focal adhesion kinase (FAK) [168] have been suggested as crucial players in the invasion and motility of breast cancer. Here, ESR1 is linked to breast cancer.