This is promising data but it’s very early. The authors are not really sure what the test is measuring on a cellular level, though they speculate a lot in the discussion, and we can’t yet truly infer a causal link between what’s causing the test result and disease status.

It’s is going to take a lot more validation before we get to the stage where this is clinically useful. For instance, the control group were healthy, what if instead you compared test results in CFS to another disease condition that can mimic CFS, would it still work as well? In the extreme case, the test could just be a generic flag that someone is non-specifically unwell, we just can’t tell from this data alone.