MUC5AC and cholelithiasis: These alterations have been proposed to be associated with the formation of biliary sludge (higher bile viscosity, resulting from the slow settling of particles dispersed; Figure 1A), gallbladder mucocele (progressive accumulation of mucin-laden bile and hyperplasic biliary mucosa; Figure 1C–E) and cholelithiasis (Figure 1B) by increasing the chances of developing cholesterol, calcium, and bilirubin precipitates into crystals and lithiasis [17,21,25].