Designing protein binders from scratch has long been a daunting challenge within the field of computational biology. Researchers have now developed an innovative, training-free pipeline that uses the fundamental principle of shape complementarity to design site-specific protein binders, which are then optimised to fit precisely onto chosen target sites. The researchers tested this on proteins linked to cancer, showing their ability to block tumour growth in animals. This discovery not only advances binder design but also enhances our understanding of protein folding and interactions at the molecular level.