Yes, hemo scheduled JAK2 test. That was neg, but false negs happen, so she did the bone marrow biopsy looking for the telltale megakatyocytes that have an "elkhorn" shaped nucleus indicating ET.

Later, the CALR test became available, and I tested positive for that. Some insurance companies at that time (10 yrs ago) would only pay for CALR and MPL testing if you tested neg for JAK2. That's because all that testing is very expensive, and most ET patients have the JAK2 mutation.

So docs have to stagger these tests instead of doing them all at once to make sure that insurance will pay for them.

This drags out diagnosis and stresses out patients. But insurance companies aren't known for their big hearts ...