**Acknowledgements**

This work was supported by the German Research Foundation DFG through the SPP 1666 Topological Insulators program. This book chapter reviews our previous work on 3D topological insulator quantum wires, for which we acknowledge the contributions of our collaborators: J. H. Bardarson, B. Büchner, J. Cayssol, B. Dassonneville, B. Eichler, W. Escoffier, H. Funke, S. Hampel, C. Nowka, O.G. Schmidt, J. Schumann, L. Veyrat, K. Wruck, and E. Xypakis.
