However, since PRC1 can either repress or activate the transcription of its target genes, it is both the downregulation and/or upregulation of tumor suppressors and oncogenes respectively that might participate in tumorigenicity.69,155–157 The exact role of PRC1 complexes in cancer, and in particular the importance of ncPRC1 complexes, remains to be determined. Here, PRC1 is linked to cancer.