Who gets testicular cancer?

Cancer of the testicles is the most common cancer in young men (15 to 34 years old). A man is more likely to get testicular cancer if any of the following are true about him:
Is white.
Has a father or brother who has or has had testicular cancer.
Has a testicle that did not come down into the scrotum (called an undescended testicle). This applies even if surgery was done to remove the testicle or bring it down.
Has small testicles or testicles that aren't shaped normally.
Has Klinefelter's syndrome (a genetic condition where male infants are born with an extra X chromosome).