In agreement with the above results from the T-cell clones, peptide stimulated PBMC from TB patients showed little or no TNF-α and IFN-γ production but produced significant levels of IL-4 and IL-13, especially in the tetramer positive group (Fig. 6D; using an arbitrary cut-off of tetramer responses > 0.10% as positive). The gene discussed is IFNG; the disease is tuberculosis.