What is "gcmaf"

GcMAF (or Gc protein-derived macrophage activating factor) is a protein produced by modification of vitamin D-binding protein. Its effectiveness is controversial. Proponents of GcMAF claim that it is an immunomodulatory protein that has antitumor properties and strengthens the immune system by macrophage activation. Organizations including Cancer Research UK have issued warnings informing the public that there is no reliable evidence that GcMAF is effective.