CDKN2A and neoplasm: Abnormal immunolabeling of TP53 was observed in 81% of pancreatic cancer patients and was associated with tumor dedifferentiation and loco regional recurrence; loss of p16 immunolabeling was observed in 67% of patients and was associated with lymphatic invasion and postoperative widespread metastases; loss of SMAD4 immunolabeling was observed in 60% of patients and was associated with tumor size, lymph node metastasis and lymphatic invasion [23].