I didn't examine it closely, but I note the word "cure" wasn't there anywhere.

I'd be looking for verifiable testimonials from people whose cats have had their leukemia go into remission.

An FEL rescue would likely have some really good information.

There are a couple of PTrs who have FEL+ cats - and I wonder what the pets take, if anything, to help them thrive?

Would be interesting to find out.