In addition, A. muciniphila can also increase the patient’s response to drugs by increasing the recruitment of CCR9+ CXCR3+ CD4+ T lymphocytes during the immunotherapy of tumor patients with PD-1/PD-L1 and increase the progression-free survival (PFS) of patients after treatment (Routy et al., 2018). Here, CCR9 is linked to neoplasm.