That would be Sternum as it is also called the "breastbone".
In aplastic anemia, then lab result will be decreased in all blood component( white blood cells, red blood cells, and thrombocyte).
Aplastic anemia is caused by the bone marrow failure. Bone marrow is the place that produces blood cells, so the decrease wouldn't be in the red blood cell only, but in other blood cells too. There shouldn't be any iron deficiency or decreases in the mean corpuscular volume
