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Tox21 Enricher: Web-based Chemical/Biological Functional Annotation Analysis Tool Based on Tox21 Toxicity Screening Platform

Junguk Hur, Larson Danes, Jui‐Hua Hsieh, Brett McGregor, Dakota Krout, Scott Auerbach.
Molecular Informatics (2017) DOI: PMID: 29377626


Figure 1. Screenshots of Tox21 Enricher analysis results.

(A) Analysis submission page supporting selection of chemical and biological annotation classes. Two types of inputs are available; sets of CASRNs contained within the Tox21 chemical set, or SMILES strings for identifying substructural analogues.
(B) The result summary page of the ‘Multiple Sets’ example data, including links to detailed enrichment outputs (text and Excel files), and other data digests. Top 10 most significantly enriched functional annotations within each CASRN set are presented as choices between a heatmap and a network.
The colour gradient in the heatmap (C) indicates the statistical significance of enrichment (−log10 of the Benjamini‐Hochberg adjusted P‐value).
Connections (edges) between significantly enriched annotations (nodes) in the network graph (D) are established, when there is significant overlap in terms of the CASRNs represented by pairs of nodes. The colour of a node corresponds to the class of chemical annotation, and edge thickness represents the degree of common chemicals between two annotations.
(E) The chemical/biological annotations for each CASRN in the sample set named ‘polycyclic aromatic hydrocarbons (PAHs) is visualized as a heatmap. Red cells indicate that the chemical has the annotation corresponding to the label above the cell‘s column.


Table 1. 2×2 contingency table for modified Fisher's exact test.

Note: A 2×2 contingency table for modified Fisher's exact test is constructed for the input set “BPAanalogue” consisting of 13 chemicals for enrichment analysis in the annotation term “bond:COH_alcohol_aromatic_phenol” in the ToxPrint substructure category. Modification of “−1” is applied to the typical Fisher's exact test to make the statistical test more conservative, resulting in a p‐value of 2.59E‐13.

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