ERVW-1 and amyotrophic lateral sclerosis: Of these, the env at 22q11.23 is a full length sequence and is expressed in teratocarcinoma [19]; the 19q11 env has no deletion or premature stop codon and is expressed in pleuripotent stem cells [20] and atypical teratoid rhabdoid tumors [21]; 12q14.1 has a full length transcript except for a 3 nucleotide in frame deletion and is also expressed in stem cells although at a lower level [20]; 7p22.1a encodes a full length functional envelope protein and has been implicated in ALS [22].