Similarly, the fibrotic and regulatory cytokine, TGF-β is significantly elevated in the serum of effusive-constrictive tuberculous pericarditis, leading to the hypothesis that the immunopathology seen in ECP is largely driven by a pathological cross-regulatory and fibrotic response which abrogates the protective IFN-γ response, and leads to structural changes in the visceral pericardium which are manifested by constrictive physiology. This evidence concerns the gene TGFB1 and pericardial tuberculosis.