['Uterine serous carcinoma (USC) is a subtype of endometrial cancer associated with chemoresistance and poor outcome. Overexpression of tubulin-β-III and p-glycoprotein has been linked to paclitaxel resistance in many cancers but has been undercharacterized among USCs. Epothilones have demonstrated activity in certain paclitaxel-resistant malignancies. In this study, relationships are clarified, in USCs relative to ovarian serous carcinomas (OSCs), between tubulin-β-III and p-glycoprotein expression, clinical outcome, and in vitro chemoresponsiveness to epothilone B, ixabepilone, and paclitaxel.', 'Tubulin-β-III and p-glycoprotein were quantified by real-time polymerase chain reaction in 48 fresh-frozen tissue samples and 13 cell lines. Copy number was correlated with immunohistochemistry and overall survival. Median inhibitory concentration (IC50 ) was determined using viability and metabolic assays. Impact of tubulin-β-III knockdown on IC50 was assessed with small interfering RNAs.', 'USC overexpressed tubulin-β-III but not p-glycoprotein relative to OSC in both fresh-frozen tissues (552.9\u2009±\u2009106.7 versus 202.0\u2009±\u200943.99, P\u2009=\u2009.01) and cell lines (1701.0\u2009±\u2009376.4 versus 645.1\u2009±\u2009157.9, P\u2009=\u2009.02). Tubulin-β-III immunohistochemistry reflected quantitative real-time polymerase chain reaction copy number and overexpression stratified patients by overall survival (copy number\u2009≤\u2009400: 615 days; copy number\u2009>\u2009400: 165 days, P\u2009=\u2009.049); p-glycoprotein did not predict clinical outcome. USCs remained exquisitely sensitive to patupilone in vitro despite tubulin-β-III overexpression (IC50,USC 0.245\u2009±\u20090.11 nM versus IC50,OSC 1.01\u2009±\u20090.13 nM, P\u2009=\u2009.006).'] Is tubulin-β-III overexpression by uterine serous carcinomas a marker for poor overall survival after platinum/taxane chemotherapy and sensitivity to epothilones?