Comma Emphasizing Contrasting Ideas With Commas
A group of words which offers a contrast to the subject of the sentence may need to have a comma on either side to separate it from the main idea. Look for words such as not, unlike and never; these signify a contrasting idea. By putting a comma on either side, the contrasting idea is made clear to the reader, and the subject is clearly modified.
Mary, unlike Ann, is very organised.
Tea should be steeped, never boiled.
Most people will continue wanting, but rarely needing, more and more material objects.
Ice hockey, not road hockey, is a good winter sport.