We describe here structural and expression analysis of the jun-B oncogene in two cervical cancer cell lines. In the CC7T-a cell line, results from both Southern analysis and cDNA cloning studies revealed the existence of two structurally altered jun-B alleles besides the normal gene. One of the altered alleles was due to a type 16 human papillomavirus (HPV-16) integration event, whereas the other allele was a consequence of a chromosomal translocation involving chromosome 19 (jun-B) and an EST182 locus residing in chromosome 15. In the HeLa cell line, which contains integrated HPV-18, an apparent structural aberration, a 3-fold amplification and a 3-fold overexpression of the jun-B gene were observed. Our observations suggest that deregulation of the jun-B gene expression may have contributed to the transformation process in these two cervical cancer cell lines.