A set of 53 BAC and 50 other lung cancer samples from lung cancer patients seen at the MD Anderson Cancer Center were analyzed for expression of JSRV Gag and Env proteins by Mab and polyclonal rabbit antiserum staining of fixed tumor-bearing lung tissue [Table 1; BAC samples 1–53 and other lung cancer (LCA) samples 1–50]. Here, ERVW-1 is linked to minimally invasive lung adenocarcinoma.