Extremely troublesome sponsors
Let me start by saying I LOVE this app. And that's why I was really sad to see that your app, that is about education and learning, has accepted the sponsor "Immunotherapy" which is a scheming company implying you can beat cancer through your immune system. No such research exists at the moment and Duolingo shouldn't take part in spreading the lies. I actually think this type of advertisement is dangerous. I understand you need the money, but is this really worth it?
I had not heard of this before. Some research into medical literature and the like does reveal some skepticism, but seems to have been moving towards being more accepted in recent years, and I do not see any rejection quite on the level of what you're suggesting.
I recommend citing a publication from a respectable source that denounces these practices, if you want to back up your claim.
William Coley's Cancer-Killing Toxins. He started it all. https://en.wikipedia.org/wiki/William_Coley
If you can wake up (again), unleash and target your immune system against it you should probably have unleashed the biggest and most successful fighter against cancer ever.
I'm all for supporting fighting cancer, but yes, I have never heard of beating it through your immune system. Do the staff realize this is fake?
Immunotherapy for cancer is real. It is a recent development.
But the decision to use it, has to be made by a doctor.
So I agree with your complaint "your app, that is about education and learning, has accepted the sponsor "Immunotherapy"."