In the CUMS-induced depression study in mice, the β-diversity was also different between non-responders and responders (Duan et al., 2021), as was the β-diversity in patients who did and did not benefit from anti-programmed cell death protein 1 (PD-1) immunotherapy (Mao et al., 2021). The gene discussed is PDCD1; the disease is depressive symptom measurement.