An informative human TB patient study compared peripheral blood iNKT cells from active TB patients, latent TB patients and healthy controls and found reduced cell proliferation of iNKT cells in response to αGalCer ex-vivo. They further showed that this was a cell intrinsic defect owing to reduced CD1d expression, increased PD-1 expression and increased apoptosis in iNKT cells from active TB patients in comparison to latent TB or healthy control groups. This evidence concerns the gene CD1D and tuberculosis.