Despite extensive investigations, a microbiological cause for cutaneous ulceration was suggested in only five individuals, including three with positive deep-wound cultures for Staphylococcus aureus [26, 29, 30], one where human herpesviruses and Ebstein-Barr virus were detected via PCR [38], and one with suspected toxoplasmosis based on positive IgM serology [15]. The gene discussed is CD40LG; the disease is toxoplasmosis.