This code system http://www.genenames.org/geneId defines many codes, of which the following are a subset:
| Code | Display | Definition |
| HGNC:4931 | HLA-A | major histocompatibility complex, class I, A |
| HGNC:4932 | HLA-B | major histocompatibility complex, class I, B |
| HGNC:4933 | HLA-C | major histocompatibility complex, class I, C |
| HGNC:4934 | HLA-DMA | major histocompatibility complex, class II, DM alpha |
| HGNC:4935 | HLA-DMB | major histocompatibility complex, class II, DM beta |
| HGNC:4936 | HLA-DOA | major histocompatibility complex, class II, DO alpha |
| HGNC:4937 | HLA-DOB | major histocompatibility complex, class II, DO beta |
| HGNC:4938 | HLA-DPA1 | major histocompatibility complex, class II, DP alpha 1 |
| HGNC:4939 | HLA-DPA2 | major histocompatibility complex, class II, DP alpha 2 (pseudogene) |
| HGNC:19393 | HLA-DPA3 | major histocompatibility complex, class II, DP alpha 3 (pseudogene) |
| HGNC:4940 | HLA-DPB1 | major histocompatibility complex, class II, DP beta 1 |
| HGNC:4941 | HLA-DPB2 | major histocompatibility complex, class II, DP beta 2 (pseudogene) |
| HGNC:4942 | HLA-DQA1 | major histocompatibility complex, class II, DQ alpha 1 |
| HGNC:4943 | HLA-DQA2 | major histocompatibility complex, class II, DQ alpha 2 |
| HGNC:4944 | HLA-DQB1 | major histocompatibility complex, class II, DQ beta 1 |
| HGNC:4945 | HLA-DQB2 | major histocompatibility complex, class II, DQ beta 2 |
| HGNC:4946 | HLA-DQB3 | major histocompatibility complex, class II, DQ beta 3 |
| HGNC:4947 | HLA-DRA | major histocompatibility complex, class II, DR alpha |
| HGNC:4948 | HLA-DRB1 | major histocompatibility complex, class II, DR beta 1 |
| HGNC:4950 | HLA-DRB2 | major histocompatibility complex, class II, DR beta 2 (pseudogene) |
| HGNC:4951 | HLA-DRB3 | major histocompatibility complex, class II, DR beta 3 |
| HGNC:4952 | HLA-DRB4 | major histocompatibility complex, class II, DR beta 4 |
| HGNC:4953 | HLA-DRB5 | major histocompatibility complex, class II, DR beta 5 |
| HGNC:4954 | HLA-DRB6 | major histocompatibility complex, class II, DR beta 6 (pseudogene) |
| HGNC:4955 | HLA-DRB7 | major histocompatibility complex, class II, DR beta 7 (pseudogene) |
| HGNC:4956 | HLA-DRB8 | major histocompatibility complex, class II, DR beta 8 (pseudogene) |
| HGNC:4957 | HLA-DRB9 | major histocompatibility complex, class II, DR beta 9 (pseudogene) |
| HGNC:4962 | HLA-E | major histocompatibility complex, class I, E |
| HGNC:4963 | HLA-F | major histocompatibility complex, class I, F |
| HGNC:4964 | HLA-G | major histocompatibility complex, class I, G |
| HGNC:4965 | HLA-H | major histocompatibility complex, class I, H (pseudogene) |
| HGNC:4967 | HLA-J | major histocompatibility complex, class I, J (pseudogene) |
| HGNC:4969 | HLA-K | major histocompatibility complex, class I, K (pseudogene) |
| HGNC:4970 | HLA-L | major histocompatibility complex, class I, L (pseudogene) |
| HGNC:19406 | HLA-N | major histocompatibility complex, class I, N (pseudogene) |
| HGNC:21196 | HLA-P | major histocompatibility complex, class I, P (pseudogene) |
| HGNC:19395 | HLA-S | major histocompatibility complex, class I, S (pseudogene) |
| HGNC:23478 | HLA-T | major histocompatibility complex, class I, T (pseudogene) |
| HGNC:23477 | HLA-U | major histocompatibility complex, class I, U (pseudogene) |
| HGNC:23482 | HLA-V | major histocompatibility complex, class I, V (pseudogene) |
| HGNC:23425 | HLA-W | major histocompatibility complex, class I, W (pseudogene) |
| HGNC:19385 | HLA-X | major histocompatibility complex, class I, X (pseudogene) |
| HGNC:33913 | HLA-Y | major histocompatibility complex, class I, Y (pseudogene) |
| HGNC:19394 | HLA-Z | major histocompatibility complex, class I, Z (pseudogene) |
