CD40LG and infection: However, analysis of the serological response to CM2, a fusion protein containing the C-terminal portion of viral protein pUL44 and a highly reactive fragment of pUL57, associated with active infection, revealed that the percentage of individuals with detectable levels of IgM and IgG antibodies to CM2 was lower in the offspring compared to their partners; in parallel, a lower percentage of naïve CD8+ cells and higher percentage of late-differentiated CD8+ cells was seen in subjects with CM2-binding IgG and IgM antibodies.