IL15 and synovial sarcoma: Finally, other Th1 inflammatory markers such as IL‐12 and IL‐15, interferon (IFN)‐γ, C‐X‐C chemokine receptor (CXCR) 3 and C‐C chemokine receptor type (CCR) 5 were found upregulated in SS lesional tissue [16], with the only exception of IFN‐γ, which was also upregulated in serum [24].