Figure 4.

 Histological appearance of the primary tumors from which Nf2- or p53-deficient fibrosarcoma cell lines were derived (left) and histological sections of the lungs of recipient animals into which each of these cell lines was injected (right). The total number of metastases produced by each cell line is indicated below. The lungs of animals injected with Nf2-deficient tumor cells (A,B) are covered with metastases (arrows indicate selected metastases), whereas none are detected in the lungs of animals injected with p53-deficient tumor cells (C,D). Note that the lung in A has hemorrhaged; blood fills much of the alveolar spaces (200×).