Glucocorticoids are a class of drugs. They are the cornerstone of anti-inflammatory and immunosuppressive therapy in humans. They are often the drug of choice when rapid and potent control of an overactive immune system is necessary. This was exemplified recently by their successful use in the treatment of patients with severe COVID-19. Unfortunately, glucocorticoids also have serious side effects that affect every organ system. Remarkably, seven decades after their introduction to clinical practice, the mechanisms by which glucocorticoids regulate an overactive immune system and the mechanisms by which they cause toxicity in different organ systems remain poorly understood. Recent findings indicate that each type of human cell has a very different response to glucocorticoids. A better understanding of how glucocorticoids work may open the path to the development of drugs or drug combinations that are as effective as glucocorticoids but have fewer side effects. This important task will, in turn, require a better understanding of how glucocorticoids work in different types of human cells.

GCgx is a scientific web application that allows scientists to study the response of different cell types to glucocorticoids. It provides a simple, mobile-friendly tool that can offer quick answers to the following questions: Is my gene of interest responsive to glucocorticoids in specific cell types? If so, how does its level of expression vary over time and how statistically significant is the change?

GCgx is composed of four tools, which can be selected with the navigation tab on the left of the screen. The dataset selection tool allows users to choose from a list of datasets in which the transcriptional response to glucocorticoids was measured in one or more cell types. Selecting a dataset will display basic information about it and clicking on the Load button will load the selected dataset for visualization by the other GCgx tools. The GC-responsive genes tool allows users to find glucocorticoid-responsive genes (up-or down-regulated in response to glucocorticoids) with user-defined thresholds of log fold-change and adjusted p-value for differential expression. The Heatmap tool allows simultaneous visualization of the response to glucocorticoids across multiple genes and cell types within a given dataset. The Dotplot tool allows visualization of the transcript abundance of a single gene of interest before and after glucocorticoid treatment, including the level of variation across biological or technical replicates.

GCgx is developed and maintained by the Franco lab at the National Institute of Arthritis and Musculoskeletal and Skin Diseases, and the Bioinformatics and Computational Biosciences Branch at the National Institute of Allergy and Infectious Diseases, both at the U.S. National Institutes of Health.

If the gene expression data from GCgx helps inform your research, please cite the paper in which we first described the tool: Cao et al. GCgx: transcriptome-wide exploration of the response to glucocorticoids. J Mol Endocrinol. 2021 Dec 10;68(2):B1-B4. PMID: 34787097

Yes. You can right-click on a plot generated by GCgx and copy or save it for personal use or for academic presentations. We do not add the GCgx name or logo to the plots, to allow users to employ the images in the manner they see fit, but we do ask that you please give due credit to the GCgx application when you display images obtained from it. If you would like to use an image from GCgx in an online or print publication of any kind (including, but not limited to, peer reviewed manuscripts or marketing materials), please contact us first.

Yes. The goal of GCgx is to grow over time, by inclusion of additional high-quality datasets that are useful to its user community. If you would like to suggest a dataset for addition to GCgx, please contact us.

1. Please be sure that you are entering an official gene symbol for the species in the loaded dataset.
2. Most genes have had one or more aliases over time; please check Entrez Gene to ensure that you are using the currently accepted symbol for your gene of interest.
3. If you have documented that you are entering an official, currently accepted gene symbol for the correct species, and it is not being displayed by GCgx, please contact us.

If you have any questions, comments, or suggestions about GCgx, please contact us