Abstract: A composition comprising mithramycin or a pharmaceutically acceptable salt or solvate thereof for use in the treatment of renal cell carcinoma. In particular, the composition is suitable for use in the treatment of clear cell renal cell carcinoma. The composition is particularly useful for use in the treatment of renal cell carcinoma associated with Von Hippel-Lindau disease or Birt-Hogg-Dubé syndrome. A composition comprising mithramycin or a pharmaceutically acceptable salt or solvate thereof for use as a cytotoxic agent against FLCN-null or VHL-null renal cell carcinoma cells.