**5. Gene expression**

Gene expression profiles in endometriosis have been studied by two groups. In one study differentially expressed genes were investigated in epithelial and stromal cells from deep endometriosis and matched eutopic endometrium using cDNA microarrays and laser capture microdissection (Matsuzaki S et al, 2004) while Smith SK , (2003) undertook a genome-wide analysis of transcript abundance and changes in transcript level between normal endometrium in the proliferative and secretory phases of the menstrual cycle, between normal and ectopic endometrium of endometriosis and between normal and RU-486 exposed endometrium.

Gene expression profiling to identify genes involved in endometriosis has shown that Cyr61 gene, which codes for cystein-rich heparin-binding protein that promotes cell adhesion, migration and neo-vascularisation was deregulated (Absenger Y et al, 2004). Overexpression of p53 in atypical endometriosis and cancer associated with endometriosis has been reported (Sainz de la Cuesta R et al, 2004). Thymosin beta 4 (Tb4) gene expression, an actin sequestering protein, was up-regulated in uterine adenomyosis(endometriosis of myometrium) in mice ( Kawahara R et al, 2003). Dysregulation of 14 genes was found to be overtly associated with endometriosis by Real- Time RT-PCR expression profiling of endometriosis (Wei Ping Hu et al, 2006).
