The majority of participants with active tuberculosis, but not latent tuberculosis infection, had a CD8+ IFN-γ response (PPD: 12/13 for active tuberculosis vs 6/21 for latent tuberculosis infection, RD1-peptides: 10/13 for active tuberculosis vs 11/21 for latent tuberculosis infection). The gene discussed is PDE6B; the disease is tuberculosis.