> From the article: "Kaptchuk . . . doesn’t argue that you can simply 'think yourself better.' 'Sham treatment won’t shrink tumors

http://www.ncbi.nlm.nih.gov/pubmed/22287549

> process by which stress may potentiate carcinogenesis and how reducing body stress may prevent cancer growth and progression. The opioid peptide β-endorphin plays a critical role in bringing the stress axis to a state of homeostasis

http://www.scienceagogo.com/news/20050725232410data_trunc_sy...

> A study from the University of Michigan (U-M) has provided the first direct evidence that endorphins - the brain's own pain-fighting chemicals - do play a role in the phenomenon known as the placebo effect

Sure throws a spanner in the works.