A family of intracellular tyrosine kinases that participate in the signaling cascade of cytokines by associating with specific CYTOKINE RECEPTORS. They act upon STAT TRANSCRIPTION FACTORS in signaling pathway referred to as the JAK/STAT pathway. The name Janus kinase refers to the fact the proteins have two phosphate-transferring domains. (mesh:D053612)
| Synonym | Reference | Specificity |
| JAK | Exact | |
| Jak | Exact | |
| JAKs | Exact |
| Identifier | Name | Relation |
| HGNC:6193 | JAK3 | isa |
| HGNC:12440 | TYK2 | isa |
| HGNC:6192 | JAK2 | isa |
| HGNC:6190 | JAK1 | isa |