Enzastaurin is a synthetic bisindolylmaleimide with potential antineoplastic activity. Binding to the ATP-binding site, enzastaurin selectively inhibits protein kinase C beta, an enzyme involved in the induction of vascular endothelial growth factor (VEGF)-stimulated neo-angiogenesis.

Hypoxia-inducible factor-1 (HIF-1) is a transcriptional complex that is activated in response to hypoxia and growth factors. HIF-1 plays a central role in tumor progression, invasion, and metastasis.

Biomarkers are substances, structures, or processes that can be measured in biological samples such as urine, blood, or saliva. A biomarker is a measurable characteristic in a biological system that changes due to disease, exposure to chemicals, or exposure to organisms.