Expansion Sequencing (ExSeq) is an innovative technology that can reveal molecular signatures at unprecedented detail and complexity. It has subcellular nanoscale resolution, retains spatial information, and has highly multiplexed capabilities that allow interrogation of hundreds and thousands of genes together with other information modalities such as lipids, sugars and proteins, all in one biological context. Its combination with the recently published Expansion Microscopy-based connectomics protocol will greatly enrich the information content of the traditional connectome. In fact, a molecularly annotated connectome (MAC) has long been thought of as a critical missing piece for understanding how the wiring diagram gives rise to behavior. I am currently developing the protocol to generate the world’s first MAC. This project, which I call WormSeq, will form the necessary building block for simulating the C. elegans nervous system with high biological fidelity.