there are two possible explanations for these results : ( a ) the microenvironmental defect of the s1/s1d mice has a more prominent effect on the development of spleen colonies than that of macrophage-layer colonies because 'steel ' locus may not be expressed significantly in the peritoneal macrophages or ( b ) because the cells that make colonies on the macrophage layer may be more differentiated cells than the multipotential stem cells that make colonies in the spleen .
C1519473
development
C0037993
spleen