KRAS and gallstones: While considering the development of gallbladder cancer, it is important to realize that there are differences in the pathophysiology of gallbladder cancer in different parts of the world.[21] The basic differences lie in the fact that the etiology, viz., gallstones or the anomalous pancreaticobiliary duct junction (APBDJ), results in certain gene mutations (K-ras and p53)[22] and consequent patterns of disease progression to the final malignant state.