Analysis of mCG-PR^2VR. (A) Colony-forming units from serial replating of bone marrow progenitors (n = 5-6/group) in 6- to 12-week-old mice. (B) Analysis of spleens from animals 2 to 6 months old for weight and immunophenotypes by flow cytometry (n = 4-9 mice/group). (C) RT-PCR for PR expression relative to GAPDH in bone marrow of 6- to 12-week-old animals (n = 4/group, performed in duplicate).