4-1

4-1 can refer to the following:
 * World 4-1 from various games
 * Level 4-1 from various games
 * Stage 4-1 from Donkey Kong for the Game Boy
 * Fury Volcano 4-1 from Super Princess Peach
 * Room 4-1 from the Mario vs. Donkey Kong series
 * Chapter 4-1 from Super Paper Mario
 * Area 4-1 from Mario vs. Donkey Kong: Mini-Land Mayhem!