However, the analysis of grade IV astrocytomas indicated a moderate correlation between the relative expression levels of Bmi-1 and CDC6 (r = 0.4704, p<0.05) (Fig 5A), Bmi-1 and RB1 (r = -0.4931, p<0.05) (Fig 5B), Bmi-1 and CCND1 (r = 0.4360, p<0.05) (Fig 5C), CDC6 and RB1 (r = -0.5109, p<0.05) (Fig 5D), CDKN2B and CDKN2A (r = 0.5287, p<0.01) (Fig 5E), and CDKN2B and CCND1 (r = -0.4597, p<0.01) (Fig 5F); there was a strong correlation between the relative expression levels of CCND1 and RB1 (r = -0.7667, p<0.001) (Fig 5G) (Table 4). Here, RB1 is linked to astrocytoma (excluding glioblastoma).