Measurement of immunoreactive intensity showed that weak immunoreactivity of RB1 was observed significantly higher (P=0.001) in brain tumor sections as compared with moderate and strong immunoreactive intensity as shown in Figure 6D. Expression analysis of CCND1 at protein level showed the increased expression of CCND1 in brain tumor section compared with control section as shown in Figure 6E,F. This evidence concerns the gene RB1 and brain neoplasm.