There are several widely used pathway databases including KEGG, BioCyc, SMPDB, as well as GEM models. All of them have different strengths and limitations in terms of pathway definition and species coverage. MetaboAnalyst aims to accommodate the diverse needs of the user community by providing multiple options.
For instance, for humans, users can either use the manually curated genome-scale metabolic model [MTF], the BioCyc metabolic model [BioCyc], or the KEGG pathway library [KEGG].