Table S1.

α2δ1⁺ HGC-27 cells displayed significant tumorigenic capacity after subsequent transplantation

Group	Tumor formation (tumor formed/mice injected)		Frequency of tumorigenic cells	(95% CI)	p-Value
	Cells inoculated
102	103
α2δ1+HGC-27(A)	3/5	4/5	1/360	(1/988–1/131)	0.0024 (A vs B)
α2δ1−HGC-27(B)	0/5	1/5	1/4,983	(1/35,191–1/706)

Notes: The tumorigenic frequency and the comparison of the frequencies between different groups was calculated based on extreme limiting dilution analysis using the web tool at http://bioinf.wehi.edu.au/software/elda/ (Hu and Smyth, 2009).³⁶ p-value <0.05 was considered statistically significant.