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.
Differences between mean (± standard error of the mean) IFN-γ responses (in international units per milliliter) to human PPD (HuPPD), avian PPD (AvPPD), bovine PPD (BoPPD), and mitogen stimulation antigens of tuberculin skin test-negative (▨) and -positive (□) individuals. *, significant difference (P < 0.01).
