Cancer is one of the leading causes of mortality in developed countries such as the USA. In 1998, there were more than 280,000 and 250,000 cancer related deaths in males and females, respectively. In males, lung and prostate cancers accounted for almost half of these deaths, whereas in females, lung and breast cancers were the leading causes of cancer mortalities. Therefore, the study of cancer has been of the utmost importance to patients, doctors, and researchers alike. A variety of cellular processes occur in the precancerous cells that contribute to the development and progression to cancer. Not surprisingly, all of these cellular processes have been targeted for anticancer therapy. A novel serpin, maspin, has demonstrated a robust effect on a variety of these cancer progression steps. A number of studies have shown that maspin inhibits angiogenesis and tumor cell growth and invasion both in vitro and in vivo. In addition, maspin promotes cell adhesion to the basement membrane and extracellular matrix components. Efforts underway to understand the molecular mechanisms involved in the diverse functions influenced by maspin have yielded promising results and shed light on the cancer pathways.