Janus kinase inhibitors: A new therapeutic option for autoimmune diseases

Many cytokines are crucial drivers of cancers and autoimmune conditions. These proteins bind to receptors and signal their responses through Janus kinase (JAK) and signal transducer and activator of transcription (STAT) pathways. Genetic variations in the JAK–STAT pathway are correlated with the increased risk of cancers, autoimmunity as well as inflammatory diseases. Targeting JAKs and STATs can be a safe and efficacious strategy for treating these diseases. Tofacitinib, as the first JAK inhibitor, is approved for rheumatoid arthritis therapy. Also, many other JAK inhibitors have been proven or are in various phases of clinical trials for various diseases. At present, small‐molecule JAK inhibitors are considered as a novel category of drugs in the treatment of cancer and immune‐mediated diseases.