... phosphorylating the retinoblastoma protein. Over-expression of CDK4 has been described in many tumors,including lung cancer. In this investigation, we analyzed the e xpression of CDK4protein in lung ... usingimmunohistochemical staining (Figure 1A-E). SpecificCDK4 protein staining was found in the cytoplasm andnucleus of normal and malignant lung tissues. Further-more, we observed that in ... Med 2010, 39(10):793-799.4. Lindberg D, Hessman O, Akerström G, Westin G: Cyclin-dependent kinase4 (CDK4) expression in pancreatic endocrine tumors. Neuroendocrinology2007, 86(2):112-118.5....