Polycomb protein family member CBX7 plays a critical role in cancer progression.

CBX7 is a polycomb protein that participates in the formation of polycomb repressive complex 1. Apart from few exceptions, CBX7 expression is lost in human malignant neoplasias and a clear correlation between its downregulated expression and a cancer aggressiveness and poor prognosis has been observed. These findings indicate a critical role of CBX7 in cancer progression. Consistently, CBX7 is able to differentially regulate crucial genes involved in cancer progression and in epithelial-mesenchymal transition, as osteopontin and E-cadherin. Recent evidences indicate a role of CBX7 also in the modulation of response to therapy. In conclusion, CBX7 represents an important prognostic factor, whose loss of expression in general indicates a bad prognosis and a progression towards a fully malignant phenotype.