1. Bogenmann, E., Mark, C., Isaacs, H., Neustein, H. B., DeClerk, Y. A., Lang, W. E., and Jones, P. A., 1983, Invasive properties of primary pediatric neoplasms in vitro. Cancer Research, 43, 1176?1186.
2. Breitkreutz, D., Bohnert, A., Herzmann, E., Bowden, P. E., Boukamp, P., and Fusenig, N. E., 1984, Differentiation specific functions in cultured and transplanted mouse keratinocytes: Environmental influences on ultrastructure and keratin expression. Differentiation, 26, 154?169.
3. Easty, D. M., and Easty, G. C., 1974, Measurement of the ability of cells to infiltrate normal tissues in vitro. British Journal of Cancer, 29, 36?49.
4. Fidler, I. J., 1978, Tumour heterogenity and the biology of cancer invasion and metastasis. Cancer Research, 38, 2651?2660.
5. Fogel, M., Altevogt, P., and Schirrmacher, V., 1983, Metastatic potential severely altered by changes in tumour cell adhesiveness and cell surface sialylation. Journal of Experimental Medicine, 157, 371?376.