Cell culture is one of the major tools of cell biologists. It has also become an integral part of the daily routine of most oncology laboratories for the purpose of karyotyping, chemoresistance testing, or basic research. It provides investigators with an opportunity to investigate many cellular parameters and interactions in an in vitro system in which the experimental conditions can be controlled and repeated With many tissues, either human or animal, the problems of cell culture are cell attachment and initial survival. Particularly the primary cultures derived from tumor specimens are a problem in many laboratories. Apart from modifications in the composition of tissue-culture plastic materials, other approaches have been used to get around this problem, such as coating of tissue-culture dishes with attachment enhancers, such as polyamino acids (1), fibronectin (2), laminin (3), and collagen (4) Since it was known that endothelial cells are capable of producing a basement membrane even in vitro, bovine cornea1 endothelial basement membrane was explored by Gospodarowicz et al. for its role in regeneration and nonregeneration of cornea1 endothelium in different species This bovine cornea1 extracellular matrix (bECM) was found useful in the cell culture of a wide range of different cells (5, 6), and bECM as well as other ECMs were employed in the cell biology of tumor cells derived from mammary carcinomas (7), urological tumors (8), and different kinds of pituitary adenomas (9, 10), as well as CNS tumors (11), which is the topic of this chapter.