Similarly, in experimentally-infected pigs, the infection dynamics and replication levels of GP4 shuffled viruses were similar with that of backbone virus VR2385, although the serum viral titers of M gene-shuffled viruses MTS1, MTS5, MTS8 and MTS57 were significantly lower than that of backbone virus VR2385 at 7 DPI, but there was no difference observed at 14 DPI. The gene discussed is CD36; the disease is infection.