This is likely related to the pauci-bacillary nature of the majority of cases of TBP, and the fact that TB pericardial effusions are the result of the predominant T-helper 1 immune inflammatory response, creating a lymphocytic exudate with a cytokine and enzyme milieu rich in IFNγ, tumour necrosis factor (TNF) alpha, interleukin-15 (IL) and ADA21, 22, 23. The gene discussed is IL15; the disease is tuberculosis.