ABSTRACT
As proposed by Flower,6 the lipocalins have been grouped into kernel and outlier members depending on the degree of amino acid sequence similarity. Thus, the kernel lipocalins share all three conserved sequence motifs, whereas the outlier lipocalins only have one or two in common. Based on nucleotide/amino acid sequence similarity and phylogenetic analyses, the lipocalins have been grouped into at least 14 clades (ref. 11; Chapters 2 and 3). This categoriza tion of the lipocalins will probably be increasingly useful as the family grows.
