PD-1-expressing γδT cells showed diminished expression of CD25, CD69, and CD127 relative to PD-1-negative γδT cells during the progression of infection (CD25, 2.88 ± 2.81% versus 6.76 ± 6.77%, P < 0.05; CD69, 5.42 ± 4.08% versus 14.46 ± 4.34%, P < 0.01; CD127, 7.91 ± 2.97% versus 21.63 ± 11.00%, P < 0.01). This evidence concerns the gene PDCD1 and infection.