The Human Tissues and Organs Resource (HTOR) cooperative agreement supports a procurement network developed by the National Disease Research Interchange (NDRI), a not-for-profit organization. By collaborating with various medical centers, hospitals, pathology services, eye banks, tissue banks, and organ procurement organizations, HTOR provides a wide variety of human tissues and organs—both diseased and normal—to researchers for laboratory studies. Such samples include tissues from the central nervous system and brain, cardiovascular system, endocrine system, eyes, bone, and cartilage.