Serena Williams wants to know why she is drug tested more than other tennis players, HuffPost reports.

Last week, Deadspin published a report saying that Williams has been tested five times in 2018, more than twice than other top women players and that a U.S. Anti-Doping Agency doping control officer came to Williams’ Florida home unannounced on June 14.

Williams was at a press conference on Sunday to discuss a Wimbledon match when she was asked to comment on the story.

“I never knew that I was tested so much more than everyone else,” she said. Until I read that article I didn’t realize it was such a discrepancy with me as well as against the other players that they listed, at least the American players — both male and female.”

The 23-time grand slam champion did not take the June 14 test because she was not home at the time.

The officer was willing to wait for Williams to return. Upon learning the USADA officer was at her home, Williams called Women’s Tennis Association CEO Steve Simon and told him she felt she was unfairly targeted, according to Deadspin.

“It would be impossible for me to not feel some kind of way about that,” said Williams. “I just found it quite interesting.”

Williams has said that she has no problem participating in drug tests to ensure that Tennis is clean, but wants everyone to be treated the same.

“How is it I’m getting tested five times? I’m OK with that. Literally verbatim I said: ‘I’m going with that, as long as everyone is being treated equally. That’s all I care about,’” she said.