Based on an investigation of tumor microarray expression data in the Oncomine Research Edition Database, the level of USP1 mRNA expression is markedly changed in several malignant tumors, including sarcoma, melanoma, gastric cancer, etc. and USP1 is aberrantly over-expressed in gastric or cervical cancer and in melanoma and sarcoma, as well as in osteosarcoma (Iraia et al., 2013). Here, USP1 is linked to osteosarcoma.