KLK3 and metastatic malignant neoplasm in the lymph nodes: Ahearn and coworkers observed that IGF-IR expression positively correlates with tumor stage in human PCa biopsies [191]; a positive correlation was also observed between the expression of IGF-II and the histologic differentiation and pathologic stage, lymph node metastasis and serum PSA (prostate-specific antigen) levels in hormone-treated PCa patients [192].