ABCB1 and neoplasm: Furthermore, compared to the healthy individuals, the tumour tissues with COS exhibited a significant downregulation in the mRNA expression profiles for ABCB1 (p-glycoprotein) and ABCC3. Our univariate logistic regression analysis revealed several predictors of chemotherapeutic response, including ERCC1, along with osteoblastic, fibroblastic, and mixed tumour subtypes.