A diagnostic triad has been proposed, comprising (1) endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) revealing caseating granulomas, (2) a positive cartridge-based nucleic acid amplification test (CBNAAT), and (3) elevated cystic fluid adenosine deaminase (ADA) levels exceeding 35 IU/L [5]. The gene discussed is ADA; the disease is Granuloma.