Why do a bone marrow examination? So there's a number of reasons to do a bone marrow. First off, when we think somebody has myeloma, the bone marrow itself helps to confirm that diagnosis. So that's one. The second is burden of disease. Do you have a little myeloma in the marrow or a lot? So we may approach things differently if you have 5 to 10% bed cells versus 80 to 90. Three, it lets us look at the remainder of the cells. There could be multiple abnormalities in the bone marrow beyond just the myeloma. So it lets us see, do you have lymphoma in there, leukemia, or precursors of those disease? The other issue is we learn about the genetic makeup of the myeloma cells, the genomics. And these are genetic abnormalities that you don't get from your mother or father or share with siblings, but genetic abnormalities within the cancer cells themselves. And there's a lot of different tests that can be sent. The first one is called karyotype, where you literally crack open 20 cells, spread them out and look for rearrangements of the genes. The next level is called FISH, fluorescent in situ hybridization, where we literally go fishing. We look to about 200 to 400 cells to find specific abnormalities that we know have impacts on patients with myeloma. And there's a number of what we call next generation sequencing platforms where we can look for a whole host of different genetic abnormalities that we're starting to know how better to manage patients who do or don't have some. The amount of tests that can be done on bone marrow biopsy are very wide ranging and can look for a spectrum of disorders and diseases of the bone marrow from nonmalignant to malignant conditions. And so there are a lot of possible reasons to have a bone marrow biopsy. Sometimes people just get a bone marrow biopsy because they have some abnormal blood counts that their doctor can't explain. But there are no other signs or symptoms of cancer and nothing is ever identified and the bone marrow looks normal and they can go on their way. Sometimes people get bone marrow biopsies routinely as part of cancer treatment and so you can have anything in between. The types of tests we're running, you can think of them as being in several major categories of type of test. There's the pathologist review, which is the pathologist literally looking at slides and tissue under a microscope. And then there are tests that are run at the microscopic or cellular or genetic level. And so these are tests that are generally run by lab techs on a machine and they're either looking for cell surface proteins on cells or the genetic makeup of the cells, the healthy cells or the cancer cells in the bone marrow. And these can give us information about the diagnosis of the patient, the effectiveness of the treatment if different treatment is required. And so there's a whole host of tests that can be run on the bone marrow. I think the overarching idea about why a bone marrow biopsy is done is that it's done because there is a question about if the blood making system in the patient's body is behaving appropriately. And this is the definitive test to understand if it is or not. So if through all the blood tests we've done we can't figure that out, then a bone marrow biopsy is necessary if that counts for main abnormal.