We asked this question with a focus on oxidative stress de-tox enzymes and identified a few that are over expressed in multiple cancers and that their over expression is bad prognosis. Some do have small molecules that target them.

http://www.ncbi.nlm.nih.gov/pubmed/24342878

Hope this helps.

Asparaginase, arginase, glutaminase,

H2S-producing enzyme cystathionine-β-synthase (CBS) in colon cancer, resulting in an increased rate of H2S production. Similarly, colon cancer-derived epithelial cell lines (HCT116, HT-29, LoVo) exhibited selective CBS up-regulation and increased H2S production, compared with the nonmalignant colonic mucosa cells, NCM356.

GSH transferase, multidrug resistance protein-1, P-glycoprotein

http://www.ncbi.nlm.nih.gov/pubmed/24864112