RB1 and neoplasm: In a large cohort of tumor specimens and a representative set of SySa cell lines, we detected a high prevalence of p-CREB (S133) expression, associated with concordant expression of its downstream targets Rb, Cyclin D1, PCNA, Bcl-xL and Bcl-2 in a large subset of primary SySa and all tested SySa cell lines.