PKP3 can also mediate the assembly of desmosomes and promote E-Cadherin maturation through Rap1 GTPase in squamous cell carcinoma (SCC) 9 cells because the lack of Pkp3 disrupts the E-Cadherin/Rap1 complex, which is a necessity for adherens junctions [123]. This evidence concerns the gene CDH1 and squamous cell carcinoma.