Vismodegib (trade name Erivedge) is a drug for the treatment of basal-cell carcinoma (BCC). It was approved by FDA on January 30, 2012 and by the European Commission on 12 July 2013, for the treatment of adult patients with symptomatic metastatic BCC, or locally advanced BCC inappropriate for surgery or radiotherapy. The drug is also undergoing clinical trials for metastatic colorectal cancer, small-cell lung cancer, advanced stomach cancer, pancreatic cancer, medulloblastoma and chondrosarcoma as of June 2011. The substance acts as a cyclopamine-competitive antagonist of the smoothened receptor (SMO) which is part of the hedgehog signaling pathway. The Hedgehog signaling pathway plays an important role in tissue growth and repair; aberrant constitutive activation of Hedgehog pathway signaling and uncontrolled cellular proliferation may be associated with mutations in the Hedgehog-ligand cell surface receptors PTCH and SMO. SMO inhibition causes the transcription factors GLI1 and GLI2 to remain inactive, which prevents the expression of tumor mediating genes within the hedgehog pathway. This pathway is pathogenetically relevant in more than 90% of basal-cell carcinomas.

4-methylimidazole (4-MEI) is a chemical compound that is not directly added to food; rather it is formed as a byproduct in some foods and beverages during the normal cooking process. For example, 4-MEI may form when coffee beans are roasted and when meats are roasted or grilled. 4-MEI also forms as a trace impurity during the manufacturing of certain types of caramel coloring (known as Class III and Class IV caramel coloring) that are used to color cola-type beverages and other foods. In recent years, evidence for the carcinogenicity of 4-MEI has raised concerns about uses of caramel color type III and IV that may expose consumers to 4-MEI and increase cancer risk.