been the subject of research of biologists for many decades. Prior to the advent of computational biology tools, biologists were unable to have access to large amounts of data and their analyses. The mountains of knowledge about the function, activity and interaction of molecular systems in cells remained fragmented. Moreover, these past studies that have identified and connected a few components or interactions one at a time, required decades of serial work. In a paper published in 2002 in Nature magazine "Cellular abstractions: Cells as computation" Shapiro raised the question: Why can't the study of biomolecular systems make a similar computational leap? Both sequence and structure research have adopted good abstractions: ‘DNA-as-string’ and ‘protein-as-three-dimensional-labelled-graph’, respectively. He believed that computer science could provide the much-needed abstraction for biomolecular systems. Together with his Ph.D. student Aviv Regev he used advanced computer science concepts to investigate the ‘molecule-as-computation’ abstraction, in which a system of interacting molecular entities is described and modelled by a system of interacting computational entities. He developed Abstract computer languages for the specification and study of systems of interacting computations, in order to represent biomolecular systems, including regulatory, metabolic and signalling pathways, as well as multicellular processes such as immune responses. These "molecular programming languages" enabled simulation of the behavior of biomolecular systems, as well as development of knowledge bases supporting qualitative and quantitative reasoning on these systems’ properties. The groundbreaking work (that initially used the π-calculus, a process calculus) was later taken over by IBM Cambridge in the UK (Luca Cardelli) that developed SPiM (Stochastic Pi Calculus Machine). In the last decade the field has flourished with a vast variety of applications. More recently, the field even evolved to a synthesis of two different fields molecular computing and molecular programming. The combination of the two exhibits how different mathematical formalisms (such as Chemical Reaction Networks) can serve as 'programming languages' and various molecular architectures (such as DNA molecules architecture) can in principle implement any behavior that can be mathematically expressed by the formalism being used. Doctor in a cell By combining computer science and molecular biology, researchers have been able to work on a programmable biological computer that in the future may navigate within the human body, diagnosing diseases and administering treatments. This is what Shapiro termed a "Doctor in a cell". His group designed a tiny computer made entirely of biological molecules which was successfully programmed in a