Using appropriate tests for monitoring hormone therapy is crucial in establishing the appropriate dosing regimen. This reduces the chance of undesirable side effects and maximizes beneficial effects. For example, excessive use of androgens (testosterone, androstenedione, DHEA, and testosterone derivatives) can activate subclinical prostate tumors which are androgen-dependent. Monitoring is especially important in older males. By the age of 70, at least 50% of men have subclinical prostate cancer. These men are especially susceptible to prostate growth stimulation by androgens.