@barbarian1 I got a BMB soon after my MGUS diagnosis nine years ago, initial ratio was about 2.5. It was a baseline that showed the status of my various bone marrow cells. This added to info from my BMB this summer. The other main advantage of a baseline BMB is if they can run genetic tests that show your risk (elevated or low) of progression and of treatment options should your MGUS progess (hopefully never). My 2025 BMB plus bloodwork and lack of symptoms showed I am still at MGUS with a 1q21 mutation (chromosome 1, location 21 duplicated). BMB have no to minor pain and do give a lot of info to doctors.