Farnesyltransferase is one of the three enzymes in the prenyltransferase group. Farnesyltransferase's targets include members of the Ras superfamily of small GTP-binding proteins critical to cell cycle progression.

Farnesyltransferase inhibitors (FTIs) are small-molecule inhibitors that selectively inhibit farnesylation of a number of intracellular substrate proteins such as Ras. Farnesyl transferase inhibitors (FTIs) represent a new class of signaling inhibitors that is emerging in the clinical arena of hematologic malignancies and that may inhibit critical growth and survival signals. FTIs are a class of experimental cancer drugs that target protein farnesyltransferase with the downstream effect of preventing the proper functioning of the Ras (protein), which is commonly abnormally active in cancer.