RAB27B and glioblastoma: Microarray profiles comparing GSLCs and non-stem tumor cells (NSTCs) isolated from primary human GBM (GBM-1) (Fig. 1A) showed that 4 out of 100 members in the Ras-superfamily (RAB26, RAB27B, RAB6B and ARL4C) were significantly up-regulated in GSLCs (P < 0.05) (Fig. 1B).