Description: FRIDAY, June 15 (HealthDay News) -- Defects in bone marrow can lead to abnormal blood cells that cause precancerous blood diseases in mice, two new studies find.

Blood cells are produced in the bone marrow. It was previously thought that red blood cells themselves were the source of these precancerous diseases, which can sometimes progress to leukemia.

In humans, these precancerous conditions can be difficult to treat, because not much is known about what causes the blood cells to become abnormal, explained researcher Louise Purton, who is affiliated with the Peter MacCallum Cancer Center in Australia, as well as Massachusetts General Hospital and the Harvard Stem Cell Institute in Boston.

Purton said her team found "that the bone marrow microenvironment can make the blood cells become abnormal, like a type of pre-leukemic disease."

The second study was conducted by a team led by Stuart Orkin, a Howard Hughes Medical Institute investigator at Children's Hospital Boston and