Postoperative pathological return (As shown in Figure 2): prostate adenocarcinoma with mucinous carcinoma differentiation (cancer cells arranged in adenoid pattern and rich in mucus); immunohistochemistry showed: P504s (partially +), CK7 (+), CK20 (partially +), CDX2 (+), B-catenin (plasma, membrane +), PSA (9). The gene discussed is KLK3; the disease is mucinous adenocarcinoma.