CD40LG and Ebola hemorrhagic fever: While we previously have had success in the serologic diagnosis of EBOV infection using heterologous antigen (for instance, BEBOV was initially identified by IgM reactivity to ZEBOV antigen [16]), the overall genetic divergence between EBOV species remains a concern, and previous data has suggested potential differences in serologic reactivity to different EBOV species in humans with EHF [25], [26].