[alnorth]

Now we know what Dillashaw popped for and why he immediately vacated the bantamweight belt. He tested positive for injected EPO, and is suspended for 2 years.

Apparently they caught him because of a new test that was developed, it used to be very hard to catch people for injectable EPO, but this new test makes it a lot easier. They went back and tested an old sample from Dillashaw and that popped too, so Dillashaw has been cheating for a long time.