I attended Dr Weisssman present this work a few years back at Dana-Farber. The somewhat long tl;dr is that while immune cells kill foreign material, normal cell

I attended Dr Weisssman present this work a few years back at Dana-Farber. The somewhat long tl;dr is that while immune cells kill foreign material, normal cells have "don't eat me" signal, CD47, a cell surface marker. Cancer cells also have CD47, the "don't eat me" signal, which helps them evade the immune system. So, blocking CD47 would cause the immune system to naturally target the cancer cells, with minimal side effect. Weissman's lab has an excellent scientific record so this is as good as it is going to get. The challenge now is to see if these dynamics work the same way in humans.