To confirm the in vitro phenotype of the EGFR/miR-338-3p/EYA2 pathway, we first investigated the effect of the pathway on breast tumor growth by injecting 4T1 cells harboring the indicated constructs and/or the miR-338-3p inhibitor into the mammary fat pads of BALB/c mice. Here, EGFR is linked to breast neoplasm.