„The Nusra Front has given ISIS until Saturday to accept mediation or face being expelled from Syria.“

http://www.bbc.com/news/world-middle-east-26390351

So, one group of sectarian Salafi beheader extremists is threatening to expel a slightly worse sister organization within Al Qaeda in Syria.
The BBC article leaves a bad taste as it comes along as a subtle advertisement in favor of the Al Nusra Front that demands that ISIS „accept arbitration within five days“.
The correct and not too far fetched interpretation is that Al Nusra hardly has any ideological-political issue with ISIS: „He demanded that ISIS halt all military operations against other rebels“.
This means that ISIS is welcome to remain on Syrian soil as long as they blow up Syrian army checkpoints and kill Alawites instead of „killing of an al-Qaeda emissary, Abu Khaled al-Suri“