mRNA gene expression analysis by RT-PCR: Murine Pvrig mRNA was detected in splenocytes isolated from wild-type C57BL/6 (+/+) mice, while human PVRIG mRNA was detected in homozygous humanized B-hPVRIG (H/H) mice. Protein expression analysis by western blot: Murine PVRIG protein was detected in wild-type C57BL/6 (+/+) mice, while human PVRIG protein was detected in homozygous humanized B-hPVRIG (H/H) mice. Leukocyte cell subpopulation analysis by flow cytometry: Humanized B-hPVRIG mice show similar immune and blood cell composition compared to wild-type C57BL/6 mice. In vivo efficacy evaluation: Anti-human PVRIG antibodies were effective in inhibiting MC38 tumor growth in humanized B-hPVRIG mice.