Racing tends to run in families, as the passion for speed and competition is passed down from generation to generation.
In MotoGP the likes of Stefan Bradl and Valentino Rossi have both grown up with fathers who raced Grands Prix before they then took on the challenge, while Kenny Roberts Senior and Junior were both 500cc World Champions – so far the only father and son pairing to have won the premier class title.
Then there are brothers who race in the World Championship at the same time, and sometimes even in the same category.
The latest siblings to have both ridden on the same weekend at a Grand Prix has as its elder half a very famous big brother: Valentino Rossi. The nine-times World Champion's younger half-brother Luca Marini made his debut as a Moto3 wild card at Misano this weekend to much fanfare, so redbull.com had a quick look at other recent brotherly pairings in MotoGP.
Marc and Álex Márquez
While the elder (still only 20) sets the MotoGP category alight in his debut season, the younger is taking Moto3 by the scruff of the neck.
Marc´s exploits are well known: a 125cc and Moto2 title and now the MotoGP Championship lead in his first year. Álex is doing a mean job in the smallest class too. He's currently fourth overall having scored three podiums in his first full season.
Chillingly Marc has said that his little brother is already faster than he was at that age – just 17 – so watch out for the latest Márquez off the production line!
Aleix and Pol Espargaró
Another hugely talented pair of brothers, and these two have actually raced against one another in the World Championship!
Aleix is the leading CRT rider in MotoGP this year and impressing everyone with his form on a supposedly inferior machine, while Pol is fighting for the Moto2 title with Scott Redding and will be moving up to MotoGP next year. The brothers now look set to come face to face on track in the premier class in 2014.
It won't be the first time that Aleix and Pol compete however, as they both rode in the Moto2 class in 2011.
Nicky and Roger Lee Hayden
The Hayden boys have come up against one another twice in MotoGP, both times at Laguna Seca.
In 2007, with Nicky as defending MotoGP World Champion, his younger sibling Roger Lee stepped onto a Kawasaki as a wild card and managed to better his big brother with a top-10 result as Nicky failed to finish the race.
Three years later the pair again rode against one another in the MotoGP race at Laguna, this time with Roger standing in for the LCR Honda team and scoring an impressive 11th place as Nicky took fifth.