The U.S. Open kicks off today, with Venus and Serena Williams both competing and the latter making a bid for her 24th Grand Slam singles title. To mark it, Nike this weekend released a highly emotional spot featuring the two sisters.

The ad, "You Can't Stop Sisters," appeared on the stars’ Instagram channels. It focuses on how the media has always played up the competition between the two siblings but suggests an alternative narrative: that both were furthering the causes of women's sport and racial equality. It’s narrated by Venus Williams, who says: “Ever since we were little girls, you’ve compared us to each other,” and ends by pointing out “It’s funny. You saw two tennis players trying to win a game. We saw two sisters changing it.”

The Williams sisters also appeared in the USTA’s “Be Open” campaign, which debuted last week and focused on the themes of racial justice and equality.

For more on what to expect at the fanless U.S. Open this year, check out Ad Age’s report by E.J. Schultz.