DDX39B and cancer: We subsequently evaluated the expression of components of the integrin/FAK signaling pathway (including ITGA5, ITGB1, and pFAKY397), as they are critical effectors in promoting the metastasis of cancer cells.29,30 We found that DDX39B knockdown resulted in decreased protein levels of ITGA5, ITGB1, and pFAKY397 (Fig. 3h).