Three of the following four letter clusters are alike in a certain way and one is different. Pick the cluster that is different from the rest.

UTS ONM GHI WVU

GHI

U →(-1)→T→(-1)→S O →(-1)→N→(-1)→M G →(+1)→H→(+1)→I (ODD) W →(-1)→V→(-1)→U