Important and statistically significant differences of cytokine concentrations were observed in groups of PDAC vs. other pancreatic tumours: patients with PDAC had higher indicators of systemic inflammation prior to surgery (mean plasma IL-6 concentration was 5.33 ng/L in the PDAC group and 3.49 ng/L in other pancreatic tumours group, p = 0.02, Kruskal-Wallis H test). The gene discussed is IL6; the disease is pancreatic neoplasm.