The Saemisch Variation of the Nimzo-Indian is quite risky, since White usually needs to sacrifice a pawn on the queenside, but the attack that is generated on the other side of the board makes this line very dangerous to meet in practice.
1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. b1c3  3... f8b4  4. e2e3  4... e8g8 