Using well-defined primer pairs, we could not detect expression of AKV-gp70 mRNA in the thymus or spleen of BALB/c and B6 mice (Figures 5A and 5B).29, 31, 37 However, retroviral gp70 mRNA was efficiently expressed in human and murine tumors and tumor cell lines,38 for example, in the BALB/c-derived colon carcinoma CT2629 and in B6-derived pancreatic ductal adenocarcinoma (AKC-5615 cells), established from a highly aggressive tumor in ATM-deficient AKC mice (Atmlox/lox;KrasLSL-G12D/+;p48Cre; Atmlox/lox (Figures 5A and 5B).39 Here, ATM is linked to pancreatic ductal adenocarcinoma.