PGP and breast cancer: Our findings showed pCR benefit of 31.3% (n=1) vs 4.5% (n=1) in Tau− and Tau+, 43.2% (n=1) vs 7.7% (n=1) in P-gp− and P-gp+, and 17% (n=1) vs 3.4% (n=1) in Topo-II- and Topo-II+ breast cancer patients.