With regard to the mechanisms of paclitaxel resistance in breast cancer, multiple factors are reported to be involved, such as the overexpression of the multidrug transporter P-glycoprotein (P-gp), altered cellular expression of the paclitaxel binding site, β-tubulin, especially βIII-tubulin, and expressional changes in the microtubule-associated protein TAU, which binds to the same site occupied by paclitaxel in microtubules [3,4,5]. The gene discussed is PGP; the disease is breast cancer.