Dong et al., in a series of 168 specimens, demonstrated high pRb expression in 41% percent of the benign, 50% of the borderline, and 71% of the malignant tumors; in this study, protein accumulation increased progressively with poorer differentiation and there was a trend for high pRb expression to be associated with an advanced stage of disease (14). This evidence concerns the gene RB1 and cancer.