CD40 and systemic lupus erythematosus: Recent studies show a close association between environmental and host genetic factors in the development or exacerbation of the autoimmune response.[28 ,29] To test whether there is an association between immune response to EBV and variants in host genes implicated in EBV infection, we determined the interactions between variants in IL10, CD40, and CR2 with anti-EBV responses in transitioning to SLE.