Figure 1.
Identification and classification of infertile men from 15 different treatment centers in California are shown for the years 1967 through 1998. CCR indicates the California Cancer Registry; −, negative; +, positive.
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.