Concretely, DDR1 interacted with ARF6 and PSD4 to facilitate the recruitment of PSD4 to ARF6 by collagen induced DDR1 signaling, thereby leading to a sustained ARF6 and MAPK signaling activation status, and enhancing migration, invasion and metastasis of HCC cells (Fig. 7K). Here, PSD4 is linked to hepatocellular carcinoma.