Transplantation of human tumour to immune deprived mice treated with anti-thymocyte serum.

Five out of 18 primary explants of human carcinomata obtained at operation have been grown progressively for a minimum of one month in thymectomized, x-irradiated mice reconstituted with syngeneic bone marrow and subsequently treated also with anti-thymocyte serum. All the tumours which proliferated were of gastrointestinal origin, growing locally but not metastasizing although direct invasion of the ribs occurred in one case. No implanted breast carcinomata grew in this system.