GZMB and neoplasm: The total number of tumor-infiltrating granzyme B+ (GrB+) effector CD8a+ T cells was greatly improved by ptgs2 and ptges KO, although the percentage of GrB+CD8a+ T cells in total CD8a+ T cells was similar between three groups and no significant difference was observed between ptgs2-KO and ptges-KO cells (Fig. 3C; Supplementary Fig. S9B).