EGR1 and breast cancer: In this regard, we reported a characteristic signature elicited by estrogenic GPER signaling in SKBR3 breast cancer cells and we identified a network of transcription factors, such as c-FOS, early growth response protein 1 (EGR-1), and connective tissue growth factor (CTGF), that may be involved in important biological functions (Pandey et al. 2009).