PTK2 and neoplasm: Histological staining of tumor sections taken at day 7 revealed that: (1) CD8+ T cells are present throughout all tumors, and (2) while CD8+ T cells infiltrating SCC FAK-WT tumors appear predominantly as individual cells, CD8+ T cells infiltrating SCC FAK−/− and FAK-KD tumors are clustered (Figure 2L).