We also found that the number of cells expressing PD-1, a co-inhibitory checkpoint molecule and a marker of T cell exhaustion [34], was significantly decreased, whereas that of PD-L1+ cells, which were considered to be non-tumor cells based on morphology, was increased in response to Am80 in tumors developed in WT mice but not Meflin KO mice (Fig. 3e and Supplementary Fig. S8). This evidence concerns the gene ISLR and neoplasm.