Strain specific IL18 expression analysis in homozygous B-hIL18 mice by ELISA. Serum were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hIL18 mice (H/H), and analyzed by ELISA with species-specific IL18 ELISA kit. Mouse IL18 was detectable in wild-type mice. Human IL18 was exclusively detectable in homozygous B-hIL18 mice but not wild-type mice.