Table 1. Characteristics of different KB resistant cell lines.

KB resistant cells	Biological changes	Resistant to
KB-MDR	P-glycoprotein ↑	VP-16, Taxol, Adriamycin, Vincristine [21], [28]
KB300-CPT	Topo I ↓	CPT [21]
KBv20c	P-glycoprotein ↑	VCR [18]
KB20aVP16	Topo II↓,	VP-16, Vincristine, Adriamycin, Doxorubicin [19]
KB7d	Topo II↓, MRP↑	VP-16, Vincristine, Adriamycin, Doxorubicin [19], [20]