DRD5 and clostridium difficile infection: To validate the predictive efficacy of CDI in real-world clinical practice, 42 patients with BCa receiving immunotherapies from FUSCC, an Asian real-world cohort, were enrolled, and expression patterns of the three most significant CDI hub genes (DRD5, SCL2A14, and IGF1) were detected using immunohistochemical staining analysis (Figure 9A).