NEW YORK (AP) — Nike CEO Mark Parker’s involvement in a doping scandal that brought down renowned track coach Alberto Salazar raises questions about whether the company _ or Parker _ will face any repercussions.

Salazar and a doctor received a four-year ban from the sport from the U.S. Anti-Doping Agency for possessing and trafficking testosterone while training top runners at the Nike Oregon Project, an elite training program bankrolled by the company. Salazar is appealing the decision.

Documents released by the USADA show Parker was aware of experiments that the coach and doctor conducted on employees and athletes, and even Salazar’s own sons, to test how supplements and medicine could enhance performance without breaking anti-doping rules. Parker said he never had any reason to believe the tests violated doping rules.

Here are some questions and answers about the controversy and the possible implications for Nike, the world’s largest sports apparel company.

WHAT WAS PARKER’S INVOLVEMENT?

Parker was briefed on Salazar’s experiments, according to emails referenced in reports released by the U.S. Anti-Doping Agency. Dr. Jeffrey Brown, an endocrinologist who worked with the Nike Oregon Project, updated Parker on an experiment Salazar was conducting on his sons with testosterone gel. Parker showed keen interest in his response.

“It will be interesting to determine the minimal amount of topical male hormone required to create a positive test,” Parker wrote.

Parker was included in other email exchanges between Salazar and Brown about the experiments.

HOW HAS NIKE RESPONDED?

Nike has vehemently defended both Salazar and Parker. The company has emphasized that none of the athletes in the Oregon Nike Project has tested positive for drugs. It has noted that the arbitration panel found Salazar never intended to violate doping rules, instead taking pains to comply with the world anti-doping code. The panel said Salazar made “unintentional mistakes.”

In an open letter to Nike employees, Parker said the tests on Salazar’s sons were not done to figure out how to cheat but were part of a plan to prevent potential sabotage against Salazar’s runners. Parker said that he wanted to understand what was going on.

“Nike did not participate in any effort to systematically dope any runners ever; the very idea makes me sick,” Parker wrote.

WHAT IS THE RELATIONSHIP BETWEEN NIKE AND SALAZAR?