Mucins are the most important organic element of mucus and they belong to family of large heavily glycosylated proteins. It is a primary structural component of mucous. It is tempting to speculate that the genetic and structural diversity of mucins, is needed for their adequate functioning at the various sites of the human body, but firm knowledge about the relationship between specific structural features and functions of mucin is still missing. There is need to through the light over the correlation of mucin function and specific structural features.