Table 1.

Glossary of relevant bioinformatic terms.

Term	Definition
Drug Repurposing	Repurposing (also called repositioning, reprofiling, retasking) is the investigation and application of existing drugs for a new therapeutic purpose.
Connectivity	A measure of match or mismatch between two signatures emerging from different sources (drug, disease or pathway). A match defines a positive connection where a mismatch defines a negative connection. Occasionally, similarity, concordance and correlations are used in similar context.
Filtering	A user selected subset of data based on chosen search characteristics.
L1000	A fluorescence-based assay to measure the gene expression levels of 978 transcripts, which are highly representative of the transcriptome. The 978 representative genes are called the landmark genes.
LINCS	Library of Integrated Network-Based Cellular Signatures. A repository of signatures from diverse cell types against variety of perturbing agent.
Perturbagen	Substance used to treat the cells in order to generate signature associated with it. Includes shRNAs, cDNAs, small molecules, drugs and biologics.
Query	A user defined list of gene for which the connectivity score is calculated with respect to all the profiles available in a database.
Signature	A characteristic pattern of gene expression associated with a phenotype, response to disease or cellular response to drug perturbation.