FN1 and infection: Figure 2 shows that compared with that in untreated CD8+ T cells, the expression of KIR2DL1 on the surface of CD8+ T cells was increased by coculture with KYSE150 cells or Fn infection. The expression of KIR2DL1 increased the most when Fn infection was combined with coculture. These results suggest that both co-culture with tumour cells or infection with Fn can increase the expression of KIR2DL1 on CD8+ T cells and that the combination of these treatments can increase the expression of KIR2DL1 most significantly.