Table 2. Effect of adjuvant ATRA on HepG2 tumor formatting rate after second transplantation.

Variables	Amount of tumor [n/N* (%)]				P** for ATRA+IRFA
	Control	ATRA	IRFA+ATRA		vs. Control	vs. ATRA
ATRA, all-trans retinoic acid; IRFA, insufficient radiofrequency ablation. *, n: the actual number of tumors formed; N: the number of transplanted tumors. **, Fisher’s exact test was used to analyze the difference in tumor formatting rate after the second tumor formation rate between different groups.
Day 3	4/12 (33.3)	0/12 (0)	0/12 (0)		0.047	−
Day 7	7/12 (58.3)	2/12 (16.7)	1/12 (8.3)		0.027	1
Day 12	10/12 (83.3)	4/12 (33.3)	3/12 (25.0)		0.012	1
Diameter at end-point ( ) (mm)	13.8±1.2	9.2±0.5	6.3±0.5		0.007	0.032