IDO2 and diffuse large B-cell lymphoma: As shown in Tables 1 and 2, positive staining for IDO1, IDO2, TDO2, and IL4I1 was observed in 6 (14.0%), 24 (55.8%), 34 (79.1%), and 12 (27.9%) of 43 DLBCL cases and in 14 (60.9%), 22 (95.7%), 10 (43.5%), and 9 (39.1%) of 23 NK/TCL cases, respectively.