Quackery Exposed: GcMaf


GcMaf or Gc protein-derived macrophage activating factor is a protein by modification of vitamin D binding protein. GcMaf results from sequential deglycosylation (The removal of the sugar entity from glycogen, a substance deposited in bodily tissues as a store of carbohydrates.) of the vitamin D binding protein. It is naturally promoted by the lymphocytes (a type of white blood cell), B and T cells. The resulting protein may be a macrophage activating factor (MAF). MAFs are lymphokines (a substance created by lymphocytes that activates the immune system)

Fake Cure-All

From 2008, GcMaf has been advertised as a cancer cure, HIV, autism, and other conditions. There were four studies authored by Yamaoto which were published between 2007 and 2009. Three of them were retracted by the scientific journals when published in 2014. This was due to irregularities in the way the ethics approval was granted. There were reportedly methodological errors in the studies. The integrity of the research triggered claims about cancer and HIV studies.

The UK Medicines Healthcare Products Regulatory Agency and Cancer Research UK warned the public about the claims of clinical benefits. The appearance of a clinical benefit was based on the reduced levels of alpha-N-acetylgaloctosamindase enzyme (nagalase which is a liver enzyme). Many cancers cause an overproduction of nagalase.

Autistic children being dosed with GcMaf were not exibiting autistic behaviors because they were suffering from horrible side effects. GcMaf is injected in the muscle or intramuscular injection.

Promotors of this dangerous substance were people such as Amanda Mary Jewell and Jeff Bradstreet. 

Side effects:

Toxic shock
abdominal pain


Galactosidases — Advances in Research and Application. Scholarly Editions. 21 June 2013. p. 52. ISBN 978-1-4816-8801-7.
“GcMAF: a story of exploitation and lies”. Anticancer Fund. Retrieved 2018-07-28.
Malik, Suneil; Fu, Lei; Juras, David James; Karmali, Mohamed; Wong, Betty Y. L.; Gozdzik, Agnes; Cole, David E. C. (January–February 2013). “Common variants of the vitamin D binding protein gene and adverse health outcomes”. Critical Reviews in Clinical Laboratory Sciences. 50 (1): 1–22. doi:10.3109/10408363.2012.750262. PMC 3613945. PMID 23427793.
Mosser, David M. (February 2003). “The many faces of macrophage activation”. Journal of Leukocyte Biology. 73 (2): 209–212. doi:10.1189/jlb.0602325. PMID 12554797.
Arney, Kat (3 December 2008). “‘Cancer cured for good?’ – Gc-MAF and the miracle cure (revised 25 July 2014)”. Cancer Research UK. Retrieved 10 February 2015.
(Retracted) Yamamoto, Nobuto; Ushijima, Naofumi; Koga, Yoshihiko (January 2009). “Immunotherapy of HIV-infected patients with Gc protein-derived macrophage activating factor (GcMAF)”. Journal of Medical Virology. 81 (1): 16–26. doi:10.1002/jmv.21376. PMID 19031451.
Miller, Michael E. (16 July 2015). “The mysterious death of a doctor who peddled autism ‘cures’ to thousands”. Washington Post. Retrieved 26 August 2015.
“Press Release: Regulator warns against GcMAF made in unlicensed facility in Cambridgeshire – GOV.UK”. Medicines and Healthcare products Regulatory Agency. 3 February 2015.
(Retracted) Yamamoto, Nobuto; Suyama, Hirofumi; Yamamoto, Nobuyuki; Ushijima, Naofumi (15 January 2008). “Immunotherapy of metastatic breast cancer patients with vitamin D-binding protein-derived macrophage activating factor (GcMAF)”. International Journal of Cancer. 122 (2): 461–467. doi:10.1002/ijc.23107. PMID 17935130.
Yamamoto, N.; Suyama, H.; Nakazato, H.; Yamamoto, N.; Koga, Y. (2014). “Retraction Note to: Immunotherapy of metastatic colorectal cancer with vitamin D-binding protein-derived macrophage-activating factor, GcMAF”. Cancer Immunology, Immunotherapy. 63 (12): 1349. doi:10.1007/s00262-014-1616-x. PMID 25297451.
“Retraction”. International Journal of Cancer. 135 (6): 1509. 15 September 2014. doi:10.1002/ijc.29014.
Ivan Oransky (25 July 2014). “Paper about widely touted but unapproved “cure” for cancer, autism retracted”. Retractionwatch.
“Tracking retractions as a window into the scientific process Yet another study of widely touted cancer “cure” retracted”. Retraction Watch. Retraction Watch. 2014-10-10. Retrieved 28 July 2015.
UK’s MHRA shuts down GcMAF plant (FDA News website)
Mann, Nick. “Man behind GcMAF is facing jail”. Retrieved 2018-09-30.
Cancer treatment developer Efranat raises $4.5 million, November 18, 2014 (Globes)
“Orphan Drug Designation – Modified vitamin D binding protein”. FDA. Retrieved 13 December 2017.
“Vitamin D binding protein macrophage-activating factor”. AdisInsight. Retrieved 7 September 2017.
Porter, Tom. “Unlicensed medical ‘cures’ are flourishing in closed Facebook groups, where cancer treatments — and even surgery — are sold beyond the reach of the law”. Business Insider. Retrieved 2019-11-14.
Evans, Ruth (2016-10-16). “Investigation over cancer ‘cure’ GcMAF”. Retrieved 2019-11-14.


2 thoughts on “Quackery Exposed: GcMaf

  1. Pingback: Rebuttal: Why the Neurodiversity Movement is Harmful → Fierce Autie

  2. Pingback: Rebuttal: Dangerous World of Marginalizing Autism Parents → Fierce Autie

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