BSG and neoplasm: Ex vivo validation confirmed significantly higher BSG/CD147 protein expression in HCC versus background liver (P = 2.9×10<sup>-11</sup>) with excellent diagnostic accuracy (AUC = 0.93-0.96; sensitivity 86-87%; specificity 93-97%) including in lesions < 2 cm that are frequently indeterminate on conventional imaging.<h4>Conclusions</h4>This study establishes BSG/CD147 upregulation as an early molecular event in hepatocarcinogenesis that integrates hepatocyte dedifferentiation, microenvironmental signaling, and tumor progression.