1. Cell signaling
D. Hanahan, R.A. Weinberg The Hallmarks of Cancer. Cell 100: (2000).

2. Cell vs. microenvironment
D. Hanahan, R.A. Weinberg The Hallmarks of Cancer. Cell 100: (2000).

3. Acquired capabilities of Cancer
D. Hanahan, R.A. Weinberg The Hallmarks of Cancer. Cell 100: (2000).

4. Stem cell self-renewal and tumorigenesis
T. Reya, S.J. Morrison, M.F. Clarke, I.L. Weissman Stem cells, cancer, and cancer stem cells. Nature 414: (2001).

5. Self-renewal capability
T. Reya, S.J. Morrison, M.F. Clarke, I.L. Weissman Stem cells, cancer, and cancer stem cells. Nature 414: (2001).

6. Heterotypic cell interactions
L.A. Liotta, E.C. Kohn The microenvironment of the tumour-host interface. Nature 411: (2001).

7. Cancer stem cell
T. Reya, S.J. Morrison, M.F. Clarke, I.L. Weissman Stem cells, cancer, and cancer stem cells. Nature 414: (2001).