Our previous study showed the presence of TLR4-expressing macrophages positive for poliovirus (PV) type 1 in 4 of 27 MG thymuses (14.8%), including two diffuse hyperplastic thymuses (or thymitis) and two thymomas, but not in 18 non-pathological control thymuses and 10 pathological thymuses (8 thymoma and 2 hyperplastic) from patients without MG, thus supporting the idea of a viral contribution to MG associated and not associated with thymoma [41]. The gene discussed is TLR4; the disease is thymoma.