I have a good friend who went through Immunotherapy on a Stage 4 lung cancer and had an impressive recovery (all the metastasis tumours disappeared in the scan

I have a good friend who went through Immunotherapy on a Stage 4 lung cancer and had an impressive recovery (all the metastasis tumours disappeared in the scan pictures I've seen). Not cured of course, but has a much longer life expectancy. So I've seen at least one anecdotal evidence that they work.