KIF4A and central nervous system cancer: Interestingly, however, KIF9 showed the highest mRNA expression in four the KIF genes, even though KIF9 was not significantly increased in LGG than in normal group (Fig. 1A lower right panel).The protein expression of KIF4A, 9, 18A, and 23 among control, low-grade glioma, and high-grade glioma was also examined using The Human Protein Atlas (HPA) portal18–20.