Blood tests and false negatives

With epigenetic dysregulations dysregulated transcription does not have to be body wide. With hypermethylated genes and histones isolated to only a few organs blood tests may be normal even though there are definite difficulties. MDs in a all probability would agree that blood tests would not pick up a lot epigenetic dysregulations but then MDs would say ‘what can we do about that?’ and continue to draw blood and do tests on blood.