A researcher discovered a drug that kills cancer stem cells, but not normal stem cells. Her fellow scientists congratulate her and tell her that she can now consider her job done. The researcher insists that more research is needed because it is important to discover HOW the drug kills cancer stem cells. Provide one reason why this additional research would be important.

As it states in the question, additional research would be important because they have to know how the drug kills the cancer stem cells.

Explanation:

If they do not know how this drug kills cancer stem cells, it could lead to very harmful things in the body. If they know how it kills cancer stem cells then they will know if it also kills anything else in the body. This would prevent potential issues in the body when using this drug.