We are making every effort to ensure that the information available on our website is accessible to all. If you have limited English proficiency or use special adaptive equipment to access the Internet and encounter problems when using this site, please email, and we will try to provide the information you need in an alternate language or format.

To learn more about the regulations governing the accessibility of Federal electronic information products, visit the Federal IT Accessibility Initiative website at

To learn about NIH’s commitment to individuals with limited English proficiency, see

Internet Browser Compatibility

We suggest using Google Chrome (v 67 or higher), Firefox (v 60 or higher), Microsoft Edge (v 40 or higher), or Safari (v 11 or higher) to view this website. Some features may not load properly in Internet Explorer 11, though refreshing the screen may enable proper loading.

Required Plug-ins, Players, and Readers

We provide information on our website in a variety of file formats. Most of these file formats are easily read and displayed by standard web browsers or word processing programs, but some files, such as multimedia or very precisely defined documents, may require the use of additional software. Users can download and install on their computers free, add-on programs called plug-ins, readers, or players that will enable their browsers to display or play the content of these files. Below are links to the download pages for the plug-ins the NIGMS website uses. These pages are at the official websites of the companies that produce the software.



Media Players