Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The contribution of the second heart field to heart tube extension. Cartoon showing the progressive addition of second heart field progenitor cells (dark blue) to the elongating heart tube between 7.5 and 9.5 d of mouse development. In the midgestation heart (right), second heart field–derived parts of the heart are indicated in blue. (From Kelly 2012; reproduced, with permission.)
