The number of investigators focusing their attention on lactoferrin has increased dramatically in recent years. Lactoferrin is a protein with more than one known structure and a number of proposed biological functions, including several with important regulatory consequences. In many ways it has been an easy pro tein to investigate; however, there have been difficulties under standing specific structure / function relationships, particularly as it functions in vivo. Research funding dedicated to this protein has previously been limited, but is now increasing. As lactoferrin begins to emerge...