Figure 2
From: Evolving BioAssay Ontology (BAO): modularization, integration and applications
BAO 2.0 makes use of BFO as the upper-level ontology and incorporates several external ontology modules. BAO classes were mapped under appropriate BFO concepts. The BFO framework also facilitates alignment to external ontology modules. Blue boxes are examples of BAO classes categorized by BFO (black rectangles). External ontologies used in BAO are shown as red boxes and labels.