This gene encodes a membrane protein that is a member of a class of protein-tyrosine kinases (PTK) characterized by the presence of a second phosphotransferase-related domain immediately N-terminal to the PTK domain. The encoded kinase phosphorylates STAT proteins (signal transducers and activators of transcription) and plays a key role in interferon-alpha/beta and interferon-gamma signal transduction. Alternative splicing results in multiple transcript variants.,JAK1,JAK1A,JAK1B,JTK3,Epigenetics & Nuclear Signaling,Cancer,Signal Transduction,Kinase,Tyrosine kinases,PI3K-Akt Signaling Pathway,ErbB-HER Signaling Pathway,Cell Biology & Developmental Biology,Apoptosis,Inhibition of Apoptosis,Immunology & Inflammation,Cytokines,IL-6 Receptor Signaling Pathway,Protein phosphorylation,JAK1