c-fos protein was predominantly located in the nuclei of glandular epithelial cells and stromal cells. c-fos and MMP-9 protein levels in paired eutopic and ectopic endometria from women with endometriosis were significantly higher than those in the endometrium from women without endometriosis.
The aromatase gene, however, was not expressed in the eutopic endometrium from either control or endometriosis groups, and was only expressed in 50% of endometriotic implants (P = 0.044). c-fos gene expression was higher in endometriotic implants (1.32 +/- 0.13; P = 0.011) than in eutopic endometrium from patients with endometriosis (0.97 +/- 0.11) or from the control group (0.91 +/- 0.05).