Strain specific CCL4 expression analysis in homozygous B-hCCL4 mice by ELISA. Serum were isolated from wild-type C57BL/6J mice (+/+) and homozygous B-hCCL4 mice (H/H) and stimulated with 1 mg/mL LPS in vivo for 24 h and analyzed by ELISA with species-specific CCL4 ELISA kit. Mouse CCL4 was detectable in wild-type mice (A). Human CCL4 was exclusively detectable in homozygous B-hCCL4 mice but not in wild-type mice (B).