This article points out the major issue in blood testing: it&#x27;s not a panacea. So often, particularly outside the life-sciences press, the idea that we&#x27;ll be able to test for everything and that it will be useful gets shouted from the rafters.<p>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>Technology can solve the lab procedure variation issue, but can&#x27;t solve biological variation. Maybe it can alleviate the biological variation problem by making it feasible to test more frequently. However as you multiply the things you&#x27;re measuring and multiply the frequency of testing you might end up testing too many hypotheses too frequently for your statistics to be reliable.<p>I&#x27;d love to have more tests more frequently. I work in medical informatics after all. But We need to be cautious about what will come out of it and not over-promise.<p>Much as we&#x27;d like it to be true, big squishy bags of water with bits of hardened calcium in them are not computers. Anything biological is hugely more noisy and far less deeply understood than anything we deal with in information technology.