Mucins are large glycoproteins that play a crucial role in the formation of mucus, a protective and lubricating substance found in various parts of the body. They are produced by specialized cells in tissues such as the respiratory and gastrointestinal tracts. Mucins help trap pathogens, dust, and other particles, preventing them from entering the body and aiding in their removal. These molecules are characterized by their high carbohydrate content, which gives mucus its gel-like consistency. Mucins also contribute to the hydration of epithelial surfaces, ensuring they remain moist and functional. Their importance is evident in conditions like cystic fibrosis, where mucin production is disrupted, leading to severe health issues.