Compared with the wild-type MCMV (MCMVWT), the M45 mutant MCMV (MCMVM45mutRHIM) infection-induced RIPK3-dependent but RIPK1/TRIF-independent necroptosis and show weaker replication in 3T3-SA or SVEC4-10 cells [81]. Here, RIPK1 is linked to infection.