Marrow: This morning a crewmember collected Breath and Ambient air samples for the Marrow study. Marrow looks at the effect of microgravity on bone marrow. It is believed that microgravity, like long-duration bed rest on Earth, has a negative effect on the bone marrow and the blood cells that are produced in the bone marrow. …

Source: ISS Daily Summary Report - 2/05/2019