This is because we previously found that: (1) Eps8 is hugely upregulated in squamous cell carcinoma (SCC) cells derived from skin carcinomas induced by administration of the chemicals 7,12-dimethylbenz(a)anthracene (DMBA) followed by 12-O-tetradecanoylphorbol-13-acetate) (TPA) [the DMBA/TPA model; driven by mutated oncogenic H-Ras (Quintanilla et al., 1986)] when compared to normal keratinocytes and in human SCCs, and (2) it associates with both FAK and active Src in SCC cells. Here, PTK2 is linked to squamous cell carcinoma.