Table 2. Tumorsphere formation of breast cancer cells treated with Anti-EMP2 mAb.

Either 1, 10 or 50 live cells were FACS sorted into 50uL of Enhanced serum-free media (+/− 10ug/mL Anti-EMP2 mAb) per well in non-treated 384-well plates. Spheres were counted 2 weeks later. The frequency of tumorsphere-initiating cells (TIC) was calculated using the online Extreme Limiting Dilution Analysis (ELDA) calculator [http://bioinf.wehi.edu.au/software/elda/index.html]. P-values were calculated by testing for inequality in frequency between multiple groups.

# spheres / wells	Treatment	1 cell / well	10 cells / well	50 cells / well	1 / TIC frequency (95 CI)	P-value
BT474	Control	49/128	113/128	126/128	1 / 7.62 cells (6.82 – 8.5)	5.05e-15
		40/128	96/128	118/128
		22/128	105/128	120/128
	Anti-EMP2 mAb	30/128	96/128	113/128	1 / 12.99 cells (11.69 – 14.4)
		27/128	84/128	108/128
		40/128	94/128	112/128
SKBR3	Control	31/120	109/120	144/144	1 / 3.31 cells (2.93 – 3.73)	2.70e-32
		32/120	118/120	144/144
		24/120	118/120	144/144
	Anti-EMP2 mAb	12/120	66/120	143/144	1 / 8.97 cells (8.02 – 10.03)
		17/120	83/120	144/144
		15/120	87/120	144/144
SUM149	Control	171/384	ND	ND	1 / 1.98 cells (1.81 – 2.18)	5.1e-05
		144/384	ND	ND
		141/384	ND	ND
	Anti-EMP2 mAb	126/384	ND	ND	1 / 2.64 cells (2.38 – 2.93)
		127/384	ND	ND
		110/384	ND	ND