For instance, GPNMB overexpresses in a breast cancer cell line that could aggressively metastasize to bone [36], and SPP1's expression level (also called Osteopontin) is elevated in a variety of metastatic cancers [37], including colon cancer [38], hepatocellular carcinoma [39], and gastric cancer [40]. This evidence concerns the gene GPNMB and breast cancer.