Gini Coefficients as a Single Value Metric to Define Chemical Probe Selectivity

Selectivity is a
key requirement of high-quality chemical probes
and lead medicines; however, methods to quantify and compare the selectivity
of small molecules have not been standardized across the field. Herein,
we discuss the origins and use of a comprehensive, single value term
to quantify selectivity, the Gini coefficient. Case studies presented
include compounds that target protein kinases, small molecules that
bind RNA structures, and small molecule chimeras that bind to and
degrade the target RNA. With an increasing number of transcriptome-
and proteome-wide studies, we submit that reporting Gini coefficients
as a quantitative descriptor of selectivity should be used broadly.