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
The MOST frequent genetic aberration associated with pancreatic malignancy is: 
Select and explain. 
A. KRAS mutation, B. c-Src, C. SMAD4, D. IGF-1R
A: KRAS mutation
Answer: A: KRAS mutation 
Explanation: 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.