Cross-reactivity studies were performed using 94 specimens positive for anti-HAV, anti-HCV, anti-HEV anti-HIV, anti-HSV, anti-CMV, anti-EBV, anti-HTLV, anti-nuclear antibody, systemic lupus erythematosus, rheumatoid factor, toxoplasma gondii IgM, syphilis, rubella antibody, E. coli infection and yeast infection. This evidence concerns the gene CD40LG and escherichia coli infection.