SP1 and breast carcinoma: Interestingly, miR-22 has been shown to form an autoregulatory loop with SP1 in breast cancer, whereby miR-22 binds to the 3′-UTR of SP1 and represses its expression, SP1 binding to the miR-22 promoter suppresses miR-22 transcription, and miR-22 overexpression suppresses breast cancer cell growth, invasion, and metastasis [54].