Given our findings that QSOX1-S suppresses integrin/FAK and EGFR/Raf/ERK pathways, we propose that QSOX1-S may in part also suppress tumor invasion and metastasis, and promote apoptosis of HCC cells through an inhibition of the integrin/FAK and EGFR/Raf/ERK pathways. Here, PTK2 is linked to hepatocellular carcinoma.