lats gene (large tumor suppressor gene), first identified in Drosophila melanogaster, has its homologues in mouse and human. The function of lats is highly conserved from Drosophila to human. Its function includes: as a tumor suppressor gene, lats mutation will result in a tumor phenotype; phosphorylated Lats can bind to Cdc2 and regulate cell cycle; Lats may also be involved in size control mechanism via cell-cell communication. The study of lats function from Drosophila to human can provide a method to study gene functions in mammals using Drosophila as a model organism.