The following link just came across my computer screen:  http://www.ncbi.nlm.nih.gov/pubmed/20043074?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=1

It describes an experiment with breast cancer cell lines exposed, in vitro (test-tube) to 4 homeopathic remedies, showing definite adverse effects on the cancer cells.