Mucin is a type of glycoprotein that plays a crucial role in the body by forming mucus. Mucus is a slippery substance that helps protect and lubricate various surfaces, such as the lining of the respiratory and digestive tracts. Mucin is produced by specialized cells, known as goblet cells, which are found in tissues like the lungs and intestines. In addition to its protective functions, mucin also aids in trapping pathogens and particles, preventing them from entering the body. This makes it an essential component of the immune system. Mucin's unique structure allows it to retain water, contributing to the viscosity and elasticity of mucus, which is vital for its functions.