RAB27B and gastrointestinal stromal tumor: Univariate analyses showed that increased nuclear expression of Rab27B (P = 0.009), tumor diameter (P = 0.010), mitotic index (P < 0.001), AFIP Miettinen risk classification (P = 0.049), and tumor grade (P < 0.001) were associated with prognosis of GIST patients for 5-year OS rates (Table 2).