Methods for maintaining, improving or increasing the synthesis of mucins by administering a nutritional composition or supplement that contains a therapeutically effective amount of threonine are provided. The system determines whether a current file attribute setting for the requested file is correct in response to receiving the notification and changes the current file attribute setting to a correct file attribute setting in response to determining that the current file attribute setting is not correct. The gene can alternatively or additionally comprise one or more introns within coding or noncoding sequences.