In the clinical practice, few studies used two or three assays in combination to improve their isolated diagnostic power for PlTB: QFT-GIT plus polymerase chain reaction [42]; ADA plus lymphocyte percentage on PF [43]; QFT-GIT on PB, ADA and carcinoembryonic antigen (CEA) on PF [2]; T-SPOT.TB on PB and PF combined with ADA on PF [44]. The gene discussed is ADA; the disease is tuberculosis.