Prior studies shows that LY6K expression in normal cells mainly exists in testicular germ cells and functions in the migration of sperm cells [8], miR-500a-3p targets LY6K to suppress cell growth and cell invasion in human non-small lung cancer [19], and the expression of LY6K is upregulated by AP-1 transcription factor to facilitate cell growth and metastatic ability in breast cancer [16]. Here, LY6K is linked to breast cancer.