Which of the Following Statements Does Not Support the Concept

Which of the following statements does not support the concept of cancer stem cells?

A) Drugs such as Gleevec that reduce tumor mass may not eliminate all cells in the tumor
B) Tumor cells are not homogeneous and can express different cell-surface markers
C) Treatment with drugs that stimulate stem cell differentiation improves the efficacy of small-molecule targeted therapies
D) A key feature of cancer is that cells of a primary tumor are capable of unlimited proliferation
E) Only some cells from a tumor are able to initiate the formation of a new tumor following injection into a immunodeficient mouse