The action of TZT-1027 has been suggested to be less affected by multidrug resistance factors, including overexpression of P-glycoprotein, than that of other tubulin inhibitors (Watanabe et al, 2006a), suggesting that TZT-1027 may be effective in the treatment of taxane-refractory tumours. This evidence concerns the gene ABCB1 and neoplasm.