28.1 Introduction 28.2 Transforming viruses carry oncogenes 28.3 Early genes of DNA transforming viruses have multifunction oncogenes 28.4 Retroviruses activate or incorporate cellular genes 28.5 Retroviral oncogenes have cellular counterparts 28.6 Ras oncogenes can be detected in a transfection assay 28.7 Ras proto-oncogenes can be activated by mutation at specific positions 28.8 Nondefective retroviruses activate proto-oncogenes 28.9 Proto-oncogenes can be activated by translocation 28.10 The Philadelphia translocation generates a new oncogene 28.11 Oncogenes code for components of signal transduction cascades 28.12 Growth factor receptor kinases can be mutated to oncogenes 28.13 Src is the prototype for the proto-oncogenic cytoplasmic tyrosine kinases 28.14 Oncoproteins may regulate gene expression 28.15 RB is a tumor suppressor that controls the cell cycle 28.16 Tumor suppressor p53 suppresses growth or triggers apoptosis
