ERBB2 and neoplasm: These dysregulated entities—such as receptor proteins (e.g., epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2)), tumor-associated antigens (e.g., PSA, CEA), ROS, metabolites, and nucleic acid alterations—constitute tumor-specific biomarkers and therapeutic targets, forming the foundation for molecular imaging and targeted therapy [5,6,7].