Worst-case scenario: the UEd Goblin wipes the map and burns down your house.
From Unreal Wiki, The Unreal Engine Documentation Site
- Hold down CTRL and the left button. Move the mouse sideways to pan the texture left or right.
- Hold down CTRL and the right button. Move the mouse backward or forward to pan the texture up or down, respectively.
Though the panning looks smooth, it is actually moving one unit at a time.