This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'The MOST frequent genetic aberration associated with pancreatic malignancy is: \nSelect and explain. \nA. KRAS mutation, B. c-Src, C. SMAD4, D. IGF-1R', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The most frequent genetic aberrations in pancreatic cancer is KRAS mutations seen in 60-75% of pancreatic cancers. The tumor-suppressor genes p16, p53, and SMAD4 are inactivated. SMAD4 gene is deleted in 55% of pancreatic tumors. SMAD4 gene inactivation is associated with poorer survival. Overexpression and/or aberrant activation of c-Src is also observed. Ref: Harrison, Edition -18, Page-787.', 'role': 'assistant'}]