Table 1. Ductal outgrowths generated from HER2 or DsRed expressing cells.

Normal mammary epithelial cells infected with HER2 or DsRed lantiviruses were introduced into the humanized mammary fatpads of NOD-SCID mince. We observed a three fold increase in the number of outgrowths generated by HER2 overexpressing cells compared to dsRed controls. As few as 250 Aldefluor-positive HER2 expressing cells formed outgrowths while Aldefluor-negative HER2 or DsRed expressing cells failed to form outgrowths. The results represent mean of three independent experiments.

Cell #	Unsorted		Aldefluor+			Aldefluor−
	10K	5K	5K	500	250	5K	250
DsRed	8	2	4	0	0	0	0
HER2	23	11	53	5	3	0	0