PTK2 and central nervous system cancer: α9β1, utilizing the spermidine/spermine-N1-acetyltransferase (SSAT)-inward rectifier potassium channel (Kir) pathways along with the common integrin signaling pathway (Src, FAK), is able to accelerate cell migration, while SSAT knockdown reduced the migration of glioma xenograft cells [27].