Table 1.

In vitro cytotoxicity (IC50 values) of histone deacetylase inhibitors to chemo-sensitive and -resistant EWS cell lines^a

cell line	NaB (mM)	SAHA (μM)	MS-275 (μM)
chemo-sensitive
SK-ES-1	1.43	2.85	3.72
TC71	7.85	2.96	30.71
chemo-resistant
CADO-ES	38.99	3.92	49.97
STA-ET2.1	0.61	1.58	10.06

^a 'natural' sensitivity of specific cell lines to chemotherapeutic drugs, as previously described [27,35].