IL6 and synovial sarcoma: Poorly differentiated synovial sarcoma, as in this case, is the most aggressive subtype and typically exhibits sheets of small, round cells with high levels of mitotic activity [3]. CRP elevation in synovial sarcoma is typically driven by tumour-associated inflammation and cytokine release, particularly IL-6, and may be exacerbated by tumour necrosis or secondary infection [7].