A protein which inhibits osteoclast diffraction and/or maturation and a method
for producing the protein. The protein is produced by human embryonic lung fibroblasts
and has a molecular weight of about 60 kD and about 120 kD under non-reducing conditions
and about 60 kD under reducing conditions an SDS-polyacrylamide gel electrophoresis.
The protein can be isolated and purified from the culture medium of fibroblasts.
Furthermore, the protein can be produced by gene engineering. The present invention
includes cDNA for producing the protein by gene engineering, antibodies having
specific affinity for the protein or a method for determining protein concentration
using these antibodies.
