a csf activity of 70,000 daltons was found in cultures of fibroblasts from lungs , kidneys , and the peritoneal cavity , a 45,000-dalton csf was obtained from mouse peritoneal macrophages , and from bone marrow cells when activated for macrophage proliferation , and a 22,000-dalton csf was found from epithelial cells , thus suggesting that the different csfs are cell specific .
C0016030
fibroblasts
C0007634
cell