PTGS2 and cancer: Another similar study has used the Cox-2 promoter to drive the 15-hydroxyprostaglandin dehydrogenase (15-PGDH), a gene suppressed in the majority of cancers. 15-PGDH specific expression, under Cox-2 control promoter in colon cancer cells, inhibited growth and migration of colon cells [43]. In vivo studies demonstrated a similar effect in LoVo xenografts treated with Cox-2-TK, showing 59.4% inhibitory rates versus nontreated LoVo xenografts [45].