The expression of MSRV-Env was detected in 5 out of 8 CIDP patients (Perron et al., 2012), and the protein was found in the nerve lesions of 5 out of 7 patients (Faucard et al., 2016) with a prevailing expression in Schwan cells (Faucard et al., 2016). The gene discussed is ERVW-1; the disease is chronic inflammatory demyelinating polyradiculoneuropathy.