– Growth/differentiation factor 11(GDF-11) is a secreted protein, which belongs to the transforming growth factor beta superfamily. GDF-11 controls anterior-posterior patterning by regulating the expression of Hox genes. The secreted signal acts globally to specify positional identity along the anterior/posterior axis during development. GDF11 has been shown to suppress neurogenesis through a pathway similar to that of myostatin, including stopping the progenitor cell-cycle during G-phase. The similarities between GDF11 and myostatin imply a likelihood that the same regulatory mechanisms are used to control tissue size during both muscular and neural development.