The materials on the Picpng Website are protected by United States copyright law except that no copyright is claimed in any work of the US government. Users may download material from this site (one machine-readable copy and one print copy per page) for personal, noncommercial use only. Except where otherwise permitted below, any further reproduction, distribution, transmission, display, publication, or broadcast requires the prior written permission of AAAS.
Articles published under either a CC BY-NC or a CC BY license will clearly indicate which of these two licenses govern its use. To determine what uses of these articles do not require further permission from AAAS, see http://creativecommons.org/licenses/by-nc/4.0/legalcode (for content published under the CC BY-NC license); or https://creativecommons.org/licenses/by/4.0/legalcode (for content published under the CC BY license).
Materials available in the Teaching Resources sections of Picpng's websites (including but not limited to Picpng Signaling/STKE and SAGE KE) may be downloaded, printed, linked to, and/or redistributed for noncommercial, course teaching purposes only provided such materials are not altered or modified in any way and provided credit to the relevant site and an indication of the URL where the material appears are included.
You may not alter or remove any trademark, copyright, or other notice from copies of the content.
For further information see our guide to the Picpng Licenses for Journal Article Reuse and your Subscriber Agreement.
To contact other AAAS departments, see the Contact page.