Cysmethynil, an isoprenylcysteine carboxyl methyltransferase (ICMT) inhibitor, is primarily researched for its potential in cancer therapy. By inhibiting ICMT, it disrupts the post-translational modification of proteins, particularly Ras proteins, which are crucial for cell signaling and proliferation. This disruption can lead to the suppression of tumor growth and metastasis, making it a promising candidate for treating cancers driven by Ras mutations. Additionally, Cysmethynil is studied for its role in neurodegenerative diseases, as ICMT inhibition may help reduce the accumulation of harmful proteins in conditions like Alzheimer's. Its application extends to basic research, where it is used to understand the role of protein prenylation in cellular processes.