&gt; The problem is, it&#x27;s not that simple. Biological variation and lab procedure variation and just plain dumb bad luck makes it so that any lab test should only be considered a single datapoint. To be taken seriously, but not to be taken as &quot;the answer&quot; in and of itself.<p>And even if the results are accurate it&#x27;s often not useful. See the amount of over-diagnosis and over-treatment that results from too much testing.