SBGN

The Systems Biology Graphical Notation (SBGN) is a standard for graphically representing biochemical and cellular networks. It provides a shared set of symbols and layout rules so diagrams created by different researchers and tools convey the same meaning, supporting clear communication and computational processing of the diagrams.

SBGN comprises three complementary languages that address different aspects of biological networks: Process Description (PD), Activity Flow (AF), and Entity Relationship (ER). PD is used for detailed biochemical processes and transformations, showing molecules, reactions, and their stoichiometry along with modifiers such as catalysts and inhibitors. AF focuses on causal influences between biological activities, illustrating how one activity affects another. ER offers a higher-level representation of entities and their relationships, suitable for depicting general dependencies without detailed reaction mechanics. Each language defines its own collection of glyphs and interaction semantics.

In practice, SBGN aims to improve readability, interoperability, and data exchange across publications, databases, and software tools. Diagrams can be encoded in machine-readable formats such as SBGN-ML, enabling automated validation, rendering, and integration into computational workflows. A range of SBGN editors and viewers support diagram creation and viewing, and many pathway databases and research articles adopt SBGN to ensure consistency.

Governance and history: SBGN was developed by a community-driven effort coordinated by the SBGN Consortium, with ongoing updates to the specifications. The notation is maintained through collaboration among researchers, software developers, and database curators to promote standardized, unambiguous representation of biological networks.