PGP and neoplasm: While some studies have reported a significant association between high P-gp expression and poor prognosis, indicating that P-gp overexpression may confer a survival disadvantage by promoting drug resistance and tumor progression, others, including the present study, have failed to demonstrate such a correlation, suggesting that P-gp expression may not be an independent prognostic factor in osteosarcoma.[7–9,22,23]