In breast and colon cancer cells, CAV1 expression is repressed by methylation; however, exposure to Methotrexate or Etoposide, and presumably other cytotoxic drugs, induces CAV1 transcription, likely via promoter demethylation, and CAV1 expression mediated by ERK phosphorylation/activation and ROS production. The gene discussed is CAV1; the disease is colonic neoplasm.