HLA-DQA1 and osteosarcoma: All three cases harbored two large CN-LOH events (in the A-C-B-class III-DRA, and DQB1-DP or DRB1-DQ-DP regions), and the two osteosarcoma tumors also had small LOH or CN-LOH in DRB1-DQA1-DQB1 (81 kb), or DRB1-DQA1 (48 kb) and DQA1-DQB1 (28 kb) (data not shown).