HLA-DRB1 and internet addiction disorder: Japanese researchers also compared the human leukocyte antigen (HLA) signatures between ICI-induced IAD and idiopathic IAD (IIAD) and found no specific HLAs associated with ICI-induced IAD (12), while IIAD had significantly higher frequencies of HLA-DRB1*09:01, HLA-DQA1*03:02, and DQB1*03:03 than healthy controls.