The flow cytometric analysis of T cells isolated from tumor tissues revealed that the combination of B. longum 420 and anti-PD-1 antibody treatment increased tumor-infiltrating CD8+, and CD107a+CD8+ T cells (p = 0.734, and 0.257, respectively), while anti-PD-1 antibody alone and combination with B. longum 420 increased CD4+ T cells compared to the other treatment groups (p = 0.55, Fig. 2b), even though there was not significant difference. Here, CD4 is linked to neoplasm.