TXNRD2 and infection: In addition, to determine whether the double deletion of the TR and ROP16 genes affected IL-12 production in the host, the mice were infected with tachyzoites of the RH, TR-KO, ROP16-KO, or TR-ROP16-KO strains, and serum samples were obtained at 0.5, 1, 2, 4, and 6 h post infection for IL-12 detection by ELISA.