CDKN2A and metastatic malignant neoplasm in the lymph nodes: Studies have shown an association between Treg infiltration into the liver and recurrence of tumor metastases and multicentric cancer after hepatic resection (164), coinfiltration by FOXP3+ Treg and B7-H1+PD-1+ T lymphocytes with high-risk breast cancer (165), density of FOXP3+ lymphocytes with lymph node metastases of pancreatic cancer (166), and expression of FOXP3 and p16INK4a with progression of cervical cancer, more specifically with lymph node metastasis (167).