In a simple definition, cancer is a disease of the cells, which is caused by gene mutations. For a proportion of patients, including women with hormone receptor positive breast cancer, gene expression profiling has a substantial impact on treatment decision-making by determining which patients might—or might not—respond to particular treatment options.
A story is told that after first obtaining approval for marketing Premarin in 1942, Wyeth Laboratories didn’t lock up the secret recipe for making the hormonal drug in a company safe, to be guarded by patent lawyers.
