Vδ2+ T cell FasL expression levels in peripheral blood of TB patients with “mild” lesions, “moderate” lesions and “severe” lesions were 0.012% (0.009%, 0.032%), 0.044% (0.019%, 0.083%) and 1.15% (0.84%, 1.32%), respectively. The gene discussed is FASLG; the disease is tuberculosis.