Ovarian cancer
GPC3 mutations do not occur in the coding sequence of this protein. Ovarian cancer cell lines do not express GPC3 due to hypermethylation of the GPC3 promoter. After removing these methyl groups, the authors restored expression of GPC3. Mesothelioma cell lines contain a GPC3 promoter which is incorrectly methylated. Re-establishing expression of GPC3 prevented colony-forming by cancerous cells.