Antigens
Chemical markers found on disease-causing agents, such as cancer cells. Each type of cancer has its own specific antigens.

Phase 3 Clinical Trial
A study that evaluates a product's safety and effectiveness in patients. A Phase 3 trial can only take place if the product has successfully completed earlier studies, Phase 1 and Phase 2 trials. Once a Phase 3 trial is completed, the company producing the product can apply for approval to bring the product to market.

Androgen Independent Prostate Cancer (AIPC)
An advanced stage of prostate cancer. In AIPC, a man's cancer is progressing even though he has had hormone therapy intended to slow the cancer.

PSA
Prostate-specific antigen. PSA levels are measured by a frequently used blood test. This test is used to detect potential prostate problems and can also be used to monitor the progress of prostate cancer.

Immune System
The body's built-in defense against disease. The immune system is comprised of a variety of specialized cells that detect and attack abnormal or harmful cells (e.g. viruses, cancer cells) in the body.

Antigen Presenting Cell (APC)
A type of immune cell that recognizes abnormal cells in the body, such as cancer cells.

Hormone Therapy
A treatment for prostate cancer that aims to slow the spread of cancer by depriving the cancer cells of the male hormone testosterone. Many hormone therapies are medicines; another type is surgical removal of the testes. Hormone therapy is also commonly referred to as "androgen deprivation therapy," or ADT.

T Cell
A type of immune cell that when working correctly attacks disease-causing agents in the body, such as cancer cells.

Gleason Score
A laboratory test that determines how aggressive (fast-growing) a man's prostate cancer is. The test is done soon after prostate cancer is diagnosed.

APC
Antigen presenting cell, a type of cell that recognizes abnormal cells in the body, such as cancer cells.

Immunotherapy
A type of treatment that uses the natural defenses of the body's immune system to fight disease.

Plecebo-controlled Trial
A clinical research study in which an inactive substance (placebo) is compared to the investigational product being studied, so that the effects of the product can be determined.