PKD1 and central nervous system cancer: Extended studies of ZKK3’s properties showed that it inhibits about 70 percent of the activity of seven kinases, ERK8, PKD1, NEK2a (never in mitosis (NIMA)-related kinase 2a), PIM1, PIM3, IGF-1R (insulin-like growth factor-1 receptor), and IR (insulin receptor), that play an important role in the invasiveness of gliomas [98].