To further investigate this positive correlation and its possible therapeutic implications, a selective << COX-2 >> inhibitor, [[ etodolac ]], was tested on three variants of HT-29 colon cancer cell lines, HT-29/Inv1, HT-29/Inv2 and HT-29/Inv3, with graded increases of in vitro Matrigel invasive potential and COX-2 expression levels.