KLRG1 and neoplasm: After confirming that sE-cad could inhibit T cell activation using the in vitro assay of tumor/macrophage-mediated CD8+ T cell activation (Additional file 1: Fig. S5b), we tested if a neutralizing anti-KLRG1 antibody could reverse the inhibitory effect of sE-cad on T cell activation and found that the anti-KLRG1 antibody was able to significantly reduce the inhibition of T cell activation by sE-cad (Additional file 1: Fig. S5c).