The CO-TRANS-NET project aims to develop innovative diagnostic and therapeutic tools for cancer based on synthetic nucleic acids. It combines the programmability of DNA nanotechnology with the sensitivity and versatility of cell-free systems to build co-transcriptional networks that, in one pot, recognise tumor biomarkers, including proteins, small molecules, and antibodies, and trigger the in-vitro transcription of functional RNAs. The transcribed RNAs can either generate a measurable signal for ultrasensitive biomarker detection or act as therapeutic agents that target cancer cells.