PGP and breast cancer: While some studies have reported a significant association between high P-gp expression and poor prognosis or chemoresistance such as childhood soft-tissue sarcoma and breast cancer, others have failed to demonstrate such a correlation such as colorectal cancer and ovarian carcinoma.[18–21] This discrepancy may be attributed to several factors, including differences in tumor types, P-gp detection methods, and the complex interplay of other resistance mechanisms.