Col1a1-Cre (3.6-kb) activity covers osteoblasts and fibrocytes in bone marrow.
Constitutive activation of β-catenin by Col1a1-Cre (3.6-kb) results in fibrosis.
Fibrocytes are expanded in bone marrow under the stimulation of β-catenin.
Immunoregulatory responses accompany the fibrotic process in bone marrow.