Although the underlying mechanism(s) accounting for the differences in gene complements observed within the two cell lines was not determined, it likely stems from their distinct genetic contexts—HT1080 are a fibrosarcoma line harboring genetic alterations in the DNA damage response (WRN and ERCC5) and apoptotic (BID) pathways [9], while hTERT are a “normal” immortalized fibroblast. This evidence concerns the gene ERCC5 and fibrosarcoma.