The somatic diversity through VDJ recombination involving antiviral-related V-genes in the IgM repertoire was found high; the most abundant VDJ combination consisted of the HV1-69 gene with certain D and J genes as depicted in gray and red (Figure 3), which might be the reason for the preferential usage of that HV1-69 in many other viral diseases (Sui et al., 2009). Here, CD40LG is linked to viral infectious disease.