PTK2 and squamous cell carcinoma: In line with FAK's role in an anti-tumor evasion mechanism and an upregulated immune response following BI 853520 treatment in the 4T1 breast cancer model (Fig. 3b), it has been shown in mouse models of squamous cell cancer and pancreatic ductal adenocarcinoma that FAK inhibition increases immune surveillance, enhances the sensitivity to T cell immunotherapy and treatment with PD-1 antagonists, and ultimately delays tumor progression54–56.