1.d4 Nf6 2.c4 g6 3.Nc3 d5
In the Grunfeld, Black is willing to cede control over the center and then counter-attack. In the main line after 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7, white can try Bc4 and then Ne2 or try 7.Nf3 c5 8.Rb1