With over 679 articles published through the National Library of Medicine, 329 of which are on its use for cancer, Mistletoe has the ability modulate the intrinsic and extrinsic metabolic pathways of tumor cells, and is a proven adjunct in the treatment of cancer.  Numerous studies show its effect on tumor growth inhibition, stimulation of immune response, and improvement of quality of life.  A recent review of clinical trials with 74 patients, in whom they found regression of cancer in 38% of patients, prevention of tumor recurrence in 47% of patients, and no major therapeutic improvement in 15% of patients.  Interestingly, the authors note that there was no obvious health worsening in any of the patients during the follow up period at all.