SMAD4 and cancer: The aberrant expression of other cancer-related molecules such as p53 and SMAD4 was also more frequent in type 2 (64.3% and 42.9%) than in type 1 (9.1 and 9.1%) [111,114,130], supported by frequent mutations in PT53, PICK3CA and SMAD4 in type 2 IPNB than type 1 (Table 8) [111,130,135].