The TGF-ß cellular signaling network, essential to various functions in all metazoans and involved in many severe human pathologies like autoimmune diseases and cancer, is more flexible than previously thought. Researchers at the MPI for Neurobiology of Behavior and the MPI for Biology discovered an unknown genetic variability in this signaling pathway amongst different nematode species resulting in morphological and behavioral variations. This fresh view on the TGF-ß machinery, published in Molecular Biology and Evolution, is important for understanding the evolution of signaling pathways, their adaptability to acquire novel functions and for new strategies to control parasitic nematodes.