Table 2. Combined antitumor activity of ATRA and bortezomib against human neuroblastoma cancer xenografts.

Groups	No. of animalsStart End	RTV	T/C%	Inhibition Rate (%)
control	6 6	16.6±2.6		--
ATRA 5 mg/kg	6 6	11.1±2.7	68.9	27.9
Bortezomib 0.5 mg/kg	6 6	9.4±2.4	54.0	40.8
ATRA+ bortezomib	6 6	5.3±1.1**	37.4	56.8

**: P<0.001,vs ATRA.