NCI is collaborating with investigators from Children’s Oncology Group, which includes institutions from Canada, Spain, the United Kingdom, Italy, Turkey, Brazil, and other countries, on a retrospective study of genetic risk factors for osteosarcoma (OS). This study identified SNPs in GRM4, and 2p25.2 associated with OS risk. A replication genome-wide association study, fine mapping of risk loci, and somatic sequencing of tumor tissue are underway.