That is, both the Vδ1 and Vδ2 subsets of human γδ T cells can recognize certain ectopically expressed self-proteins on the cell surface, including NCL and hMSH2, which are produced because of exposure to stress, such as infection or malignant transformation, and play roles as first-line defense mediators and sensors for immunosurveillance. Here, MSH2 is linked to infection.