Overexpressed in endometrial CSCs; Most abundantly secreted by non-prostate CSCs and enhances the invasiveness and metastatic dissemination of prostate CSCs in a paracrine manner; plays a key role in maintaining dormancy of prostate cancer cells by upregulating BMP7 in bone marrow stromal cells; SPARC is highly expressed by HSCs that recently colonized the bone marrow. HSCs in a SPARC-deficient niche show an accelerated return to quiescence, thereby becoming resistant to serial 5-FU treatment. This evidence concerns the gene SPARC and prostate cancer.