This study evaluates and compares the diagnostic performance of the Lymphocyte Transformation Test (LTT), Conventional IFN-γ ELISpot, and Modified IFN-γ ELISpot assays (anti-CD3/CD28 and IL-2) in detecting drug-induced immune responses in SJS/TEN patients.<h4>Methods</h4>The study involved 20 SJS/TEN patients who were diagnosed based on clinical features, causality assessment using the Naranjo algorithm, and SCORTEN scoring for severity. The gene discussed is CD28; the disease is toxic epidermal necrolysis.