HLA-DRB1 and osteosarcoma: Of note, a study in osteosarcoma (with > 90% of primary diagnosis tumor cases) reported putative HLA associations, with several class II alleles claimed to be negatively (DRB1*03:01, DQB1*02:01) or positively (DQA1*01:01) associated with disease risk; however, only odd ratio values were described but not allele frequencies (89).