SPAG5 and breast cancer: Consistently, miR‐539 was found to directly target SPAG5 and miR‐539 was negatively associated with that of SPAG5 in PCa.15 Furthermore, EGFR was verified to be targeted and down‐regulated by miR‐539 in breast cancer and the binding of miR‐539 to EGFR serves as a biomarker of the treatment of breast cancer.27