Thus, we determined the expression of interleukin (IL)-6, IL-1, tumour necrosis factor (TNF)-α and TNF receptor 2 (TNFR2) to assess whether the inflammatory signature of RA-FLSs was retained after their differentiation into cardiomyocytes via iPSCs. The gene discussed is TNFRSF1B; the disease is rheumatoid arthritis.