Although the change of DOF1.7 and CBP1 expression by CMV(Ho)tr infection is an example of the co-relationship between hypomethylation and the change of gene expression in plants persistently infected with CMV(Ho), it remains to be elucidated whether the same event may be applied to other genes in which their promoter regions were hypomethylated. This evidence concerns the gene SERPINH1 and infection.