Radiosensitization by gemcitabine

"Radiosensitization by gemcitabine" is not a specific molecule, gene, protein, or receptor, but rather a **therapeutic phenomenon** describing how the **chemotherapy drug gemcitabine enhances the effect of radiation therapy** on tumor cells[1][3][5]. Gemcitabine itself is a nucleoside analog (anticancer drug), but "radiosensitization by gemcitabine" does not correspond to a discrete biological target; instead, it refers to a drug-induced process involving multiple pathways such as inhibition of DNA repair, depletion of dNTP pools, and cell cycle redistribution[1][3][5]. There is no canonical molecule, gene, or receptor with this designation.