Horia Tecău (] ; born January 19, 1985) is a Romanian tennis player currently ranked World No. 9 in doubles.
 He turned pro in 2003 and reached the men's doubles finals of the 2010, 2011 and 2012 Wimbledon Championships with Robert Lindstedt before winning it in 2015 with Jean-Julien Rojer, with whom he also won the 2017 US Open.
 Tecău also won the 2012 Australian Open mixed doubles title with Bethanie Mattek-Sands and the 2015 ATP World Tour Finals with Rojer.
Carly Gullickson (born November 26, 1986) is a former American professional tennis player.
Jean-Julien Rojer (] ; born 25 August 1981) is a Dutch professional tennis player from Curaçao.
 His highest ATP singles ranking is 218th, which he achieved on 15 August 2005.
 A doubles specialist, his career-high in doubles is World No. 3, which he reached in November 2015.
 His former doubles partners include Eric Butorac and Aisam-ul-Haq Qureshi.
 He currently plays with Horia Tecău of Romania, with whom he won the men's double titles in the 2015 Wimbledon and 2017 US Open championships.
 With Anna-Lena Grönefeld, he also won the mixed doubles' title at the 2014 French Open.
 He attended UCLA where he competed for the UCLA Bruins men's tennis team.
Athletic DNA (ADNA) is an American sports apparel company.
 Founded in Seattle in 2007, ADNA began by training young tennis athletes, which evolved into sponsoring Select Junior Tennis players, and then expanded to manufacturing clothing for youth and adult tennis players.
 ADNA has since spread to professional tennis, and currently sponsors players on the ATP Tour & WTA Tour.
The Men's International Professional Tennis Council (MIPTC), also called the Men's Tennis Council (MTC), was a governing body that administered the men's professional Grand Prix tennis circuit.
 It was founded in 1974 and was made up of representatives of the International Tennis Federation (ITF), the Association of Tennis Professionals (ATP) and, from 1976 onwards, tournament directors from around the world.
 Among its main responsibilities were the sanctioning and scheduling of the tournaments that comprise the Grand Prix circuit.
 Additionally it was responsible for creating a code of conduct for tennis players and its subsequent enforcement via the administration of fines and suspensions.
Robert Lindstedt (born 19 March 1977) is a Swedish professional tennis player, who turned pro in 1998, and is a doubles specialist.
 His biggest title has been the 2014 Australian Open with partner Łukasz Kubot.
 He is also a three-time Wimbledon finalist with former partner Horia Tecău.
The "Challenge of Champions" was created to be one of the richest prize money tennis events in the world.
 Created by Leo E. Fenn III in 1985 as an Invitation Only Tennis Tournament which would feature daily matches which were the equivalent to the Finals of the US Open or Wimbledon.
 It was usually held before the Masters and invited only the top eight men's tennis players in the world according to their rankings on the ATP poll.
 In 1985, creator & founder 24-year-old Leo E. Fenn III partnered with 28-year-old Mark Myden to form a company called Special Events Productions.
 SEP produced the "Challenge of Champions" Tournament which became a major player in professional tennis.
 These two entrepreneurs became the youngest producers in history of professional tennis.
 Leo & Mark acquired major fortune 500 corporate sponsors such as AT&T, VISA, Cadillac, Fila Sportswear, DeBeers Diamonds as well as negotiated two days of live weekend television coverage on NBC.
 Their title sponsorship package sold to AT&T was the largest single vent sponsorship package in professional tennis that year.
 Leo negotiated with the brand new Thomas Mack Center Arena in Las Vegas to host the inaugural event.
 The event rights were eventually sold to Pro Serve and concluded following the 1989 Challenge.
The Virginia Slims Circuit was a tennis tour consisting of a group of originally nine female professional players.
 Formed in 1970, the Virginia Slims Circuit eventually became the basis for the later named WTA Tour.
 The players, dubbed the "Original 9", rebelled against the United States Lawn Tennis Association (USLTA) due to the wide inequality between the amount of prize money paid to male tennis players and to female tennis players.
Rod Laver defeated Tony Roche 6–3, 6–4, 6–2 in the final to win the Gentlemen's Singles title at the 1968 Wimbledon Championships.
 It was Laver's third Wimbledon title, and his seventh grand slam overall.
 This was the first year when professional tennis players were allowed to compete at the Wimbledon Championships.
 Previously only amateur tennis players could compete.
Donald Dell (born June 17, 1938 in Savannah, Georgia, United States) is an attorney and was a professional tennis player, U.S. Davis Cup captain, and administrator.
 Dell was one of the first professional sports agents, having represented professional tennis players Arthur Ashe, Stan Smith, Jimmy Connors, and Ivan Lendl during pro tennis' golden age (1975 to 1985).
 He was also the founder of Professional Services (ProServ), one of the nation's first sports marketing firms established in 1970 with co-founder, Frank Craighill, a fellow law partner.
 His younger brother, Dick, worked for ProServ managing US Open champion Gabriela Sabatini, and played Number One Singles for the University of Michigan.
 He was Big Ten #1 Singles Champion in 1969.

Question: Were Horia Tecău and Carly Gullickson professional tennis players?
Answer: yes