PTK2 and skin neoplasm: FAK is also required for tumor initiation: organ-specific deletion of FAK suppresses mammary tumorigenesis (Luo et al., 2009; Pylayeva et al., 2009), intestinal tumorigenesis (Ashton et al., 2010), skin tumor formation (McLean et al., 2004) and hepatocarcinogenesis (Shang et al., 2015), suggesting that inhibition of FAK may present a promising strategy for treating these diseases.