STAT4 and synovial sarcoma: The genome-wide association study revealed that genes associated with susceptibility to SS (such as interferon regulatory factor 5 (IRF5), signal transducer and activator of transcription 4 (STAT4), and 2′-5′ oligoadenylate synthetase 1 (OAS1)) encode transcription factors correlated with type 1 IFN activity [26,27].