Curley's wife is rejected. We can see this point in three distinct ways in Of Mice and Men. First, she is not even given a name. This is a noteworthy point, because every character has a name except for her. Even the man who was briefly with them and left, a nobody, is given a name, Bill Tenner. This show that Curley's wife has no place on the ranch.
Second, she is a newlywed, but she is in a loveless marriage. This means that she probably did not want to marry him. If we dissect this relationship, we can say that she probably did not have much of a choice in marrying Curley. This shows that women do not have much freedom in this world. They are second class citizens.
Finally, on the ranch, all the men shun her. They think that she is trouble. The men say that she has the eye.
“Well—she got the eye."
“Yeah? Married two weeks and got the eye? Maybe that’s why Curley’s pants is full of ants."
“I seen her give Slim the eye. Slim’s a jerkline skinner. Hell of a nice fella.
Slim don’t need to wear no high-heeled boots on a grain team. I seen her give Slim the eye. Curley never seen it. An’ I seen her give Carlson the eye.”
These points show that she is an outsider. Now as for how it relates to our world, we can say many things. First, people are still rejected and feel it. Think of racism, sexism, and classism. These are real forces in our world today. To put it another way, we have come a long way, but there is still more work to do.