The UFC rankings have taken a major hit. Over the weekend, the promotion removed three of their stars from the rankings due to those fighters being flagged by USADA for failed tests. One of them was Jon Jones, the UFC interim light heavyweight champion. Another was heavyweight Brock Lesnar. The final one was former UFC light heavyweight champion and perennial middleweight contender Lyoto Machida.
Jones had been listed as the interim champion on the rankings, and his removal could indicate that he has been stripped of that title by the promotion. The UFC has not publicly commented on that though. Jones was set to fight in a title unification bout against Daniel Cormier in the UFC 200 headliner, but was forced out of the bout just days before the July 9th event due to testing positive for two estrogen blockers.
Lesnar, the WWE superstar, returned to the cage for the first time in five years to take on Mark Hunt at the same UFC 200 event. He defeated Hunt by decision, but it came out after the fight that he failed a test for a similar estrogen blocker in pre-fight testing. Due to the time needed to actually conduct the tests, the failure wasn't discovered until after the fight according to USADA and the UFC. Lesnar also failed his fight night test for the same substance. He had been in the eight spot in the heavyweight rankings.
Estrogen blockers are banned by WADA because they can be used to mask steroid use. Jones has implied that his failure came from a tainted supplement. Lesnar, who is back with WWE, has only said that he will get to the bottom of the issue.
The final removal was Machida, who admitted to using a banned substance (though he didn't know it was banned) way back in April. It's unclear why he is just being removed now, but he was. He had been ranked in the eight spot at 185 pounds.
You can see how the removals affected the rankings here. Since Jones was also ranked highly on the P4P list, there were a lot of changes there as well.
The UFC doesn't usually publicly comment on rankings, but they could very well have a statement on Jones and his title soon based on this move.