Why Steinbeck named the book Of Mice And Men in this title?

Mice are known to be soft, smooth, and fragile animals. They require attention, protection and affection when kept among men (people in general). The mice, or fragile characters, in the novel are Lennie, Curley's wife, Candy's dog, Lennie's pup, and the mouse Lennie had in his pocket at the beginning of the novel. Each are vunerable... each are fragile and weak in their own way. The "men" are those who use them.