Global Analysis of Chemical Probes as Described in Public Databases Uncovers Major Limitations and Biases
(A) Infographic showing a human silhouette representing the human proteome and areas indicating: the proportion of the proteome estimated to be druggable but currently unliganded (green; , ); the proportion found to have been already liganded (purple; see ); and the proportion that can be studied currently with chemical tools fulfilling minimum requirements of potency, selectivity, and permeability (red; see ).
(B) Venn diagram illustrating the proportion of the 2,220 liganded human protein targets that can be studied with chemical tools fulfilling minimum requirements of potency, selectivity, and permeability.
(C) Venn diagram illustrating the number of chemical compounds fulfilling minimum requirements of potency, selectivity, and permeability.
(D) Top 50 targets with the largest number of compounds fulfilling minimum requirements of potency, selectivity, and permeability.
(E) Compound selectivity per number of targets tested uncovers a very reduced exploration of compound selectivity.
See also and .

Chemical Probe Cards for Highest-Ranked PIK3CB Compounds in Probe Miner, Comprising the Chemical Structure and the Radar Plot with the Corresponding Chemical Probe Scores
Where probes have also been curated by the Chemical Probes Portal, their expert review star rating is also displayed. Moreover, when a compound is not 10-fold selective against another protein, a danger icon (red triangle) is shown to alert the researcher that there might be selectivity liabilities when using those compounds as PIK3B chemical probes.

Probe Miner Resource
Snapshot of the overview and chemical tool pages of the resource using the human PARP1 protein as an example.
(A) Summaries of the data and statistical analyses using our algorithm. Colored icons provide immediate visual indication of the overall quality and liabilities of compounds for this target, and a link to the Chemical Probes Portal is provided when this target has expert-curated compounds in the Portal.
(B) Easy-to-navigate distribution of the 20 top-ranking probes.
(C) A compound viewer interactively linked to the distribution, which shows the chemical structure and key information for the probe, as well as the values of the six score components as a radar plot. Compounds that are also expert-curated by the Chemical Probes Portal are highlighted in blue and links to the Portal are also provided.
(D) Easy-to-navigate settings panel to enable customization of the Global Score, displays, and rankings.
(E) Individual chemical probe pages where detailed information is provided, including links to other resources, commercial availability, raw data to generate the scores, and a target profile to provide an overview of compound selectivity. To learn more about how to use and navigate Probe Miner, we prepared a video tutorial (See ).
Movie S1

Flow Diagram for the Comparison between Probe Miner and the Chemical Probes Portal

Analysis of the Ranking of Chemical Probes for the Targets PARP1, CHEK2, and OPRK1
On top, Venn diagram comparing the PARP1 chemical probes recommended by the Chemical Probes Portal (see ) and the Probe Miner resource as ranked by the predefined Global Score. Chemical structures are displayed, as well as names, a radar plot showing the six Chemical Probe scores, the Chemical Probes Portal reviewers' rating, and Probe Miner ranking when available. On the bottom, highest-ranked probes for CHEK2, OPRK1 and ABCC8. See also .