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.
Distribution of percent mammographic density, dense area, non-dense area and total area for cases, sister controls, and unrelated controls. Shown are the means of the differences between cases and sister controls, and cases and unrelated controls. P is a P value from the paired t-test, two-sided.
