Data search and visualisation
Efficient search via ontology-driven query expansion
Expression Atlas uses ontology-driven search expansion to make your searching more efficient. The terms used to annotate samples are mapped to ontology terms from the Experimental Factor Ontology (EFO). Ontology mappings allow for much richer queries using the hierarchy within the ontology, for example, searching for lung carcinoma will return matches to the keyword and also results for different subtypes such as large cell lung carcinoma (Figure 3).

Easy interpretation of results through heatmap visualisation
Gene expression results are visualised using heatmaps in which gene expression values are converted into a colour-scale image. This provides a visual representation of the expression of multiple genes across different biological conditions (Figure 4) or of a single gene across different experiments and biological conditions. We will look at these heatmaps in more detail in the section Searching and visualising data in Expression Atlas.
