GZMB and neoplasm: Examining the tumor microenvironment (TME) by immunohistochemical staining revealed that the co‐inoculation of BV2 increased the CD8 T cells' infiltration and the expression of Granzyme B. Mice bearing with BV2‐containing ALTS1C1 tumor exhibited a reduced level of circulating myeloid‐derived suppressor cells (MDSCs) and an elevated level of CD8 T cells in peripheral blood compared to the ALTS1C1 tumor‐bearing group.