Table 4.

Characteristics and Tumorigenicity of Pleural Effusion Sort Populations

	Sort population		Outcome parameters (pct of sort population)			Tumorigenicity
Population	Pct of viable cells	Pct of non− (Heme, Endo, and Meso)	CD44	EpCAM	CD117	Tumors/sites injected (Pct)
CD90+ LSLOW	0.04% ± 0.01%	0.18% ± 0.06%	48.68% ± 18.85%	34.06% ± 15.12%	0.00% ±0.0 %	6/40 (15%)
CD90+ LSHIGH	7.13% ± 0.73%	33.66% ± 3.39%	72.92% ± 7.20%	27.63% ±4.96 %	0.00% ± 0.0%	0/40
CD90−	14.01% ± 0.71%	66.17% ± 3.45%	5.55% ± 0.41%	89.01% ± 0.71%	0.03% ± 0.01%	0/40
Total	21.18% ± 0.04%	100.00% ± 0.0%

Immunophenotypic data are shown for experiment 1, in which three data files were collected during the beginning, midpoint, and end of the sort. Means and standard deviations from analyses of the three data files are shown. Tumorigenicity data are pooled results of two independent experiments in which mice were injected with 100 sorted tumor cells admixed with 10,000 irradiated (100 Gy) unsorted cells. In experiment 1 (NOD/SCID recipients), injection of CD90+ low-light-scatter cells resulted in tumors in 5 of 20 injection sites. Irradiated unsorted tumor (10,000 cells) injected into 20 sites in a total of five mice failed to cause tumors. In experiment 2 (NSG mice), the frequency of tumors was 1 in 20 sites. All xenograft tumors were confirmed human cytokeratin+ by immunohistochemistry with a noncrossreactive antibody (not shown).