2.
肺癌家族聚集性的倒漏斗图
Funnel plot of lung cancer risk associated with family history of lung cancer
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.