The results of microbiologic workup were as follows: cytomegalovirus (CMV) immunoglobulin (Ig)G antibody positive (165.1 AU/mL), CMV IgM antibody negative (0.13 AU/mL), herpes simplex virus (HSV) type 2 IgG antibody negative (0.1 RU/mL), HSV type 2 IgM antibody negative (0.1), rubella IgG antibody positive (64 IU/mL), rubella IgM antibody negative (0.35 IU/mL), Toxoplasma IgG antibody negative (0.1 IU/mL), Toxoplasma IgM antibody negative (0.17 IU/mL), Venereal Disease Research Laboratory test negative, and varicella-zoster virus IgG antibody positive (549 mIU/mL). Here, CD40LG is linked to sexually transmitted disease.