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.
Timeline. White bars represent important timepoints along G’s development. Dark gray bars represent triggering event. Light gray horizonal bars represent given treatment. Light green/orange bars represent efficacy. Time scale is not linear.
