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). This evidence concerns the gene IGF1 and clostridium difficile infection.