In this study, we sought to characterize protein expression of class III β-tubulin and EP4 across a spectrum of gynecologic stromal tumors (LMS, smooth muscle tumor of uncertain malignant potential (STUMP), disseminated leiomyomatosis, leiomyoma) and to seek correlations with subsequent chemoresponsiveness to docetaxel or EP4 inhibition as a single agent or in combination. This evidence concerns the gene PTGER4 and leiomyoma.