SP1 and cancer: The tumor suppressive role of miR-375 seems to be not only mediated by its ability to interact with E6 and E7 transcripts, but also by the targeting of host cell mRNAs preventing the expression e.g. of the transcription factor SP1 that was reported to contribute to cancer development and progression [25, 56, 57], of the ubiquitin-protein ligase E6AP which is involved in the E6-mediated degradation of p53 [24], as well as of the protein CIP2A which was shown to prevent the proteolytic degradation of MYC, a transcriptional repressor of p21 [58, 59].