This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
RAS gene codes for: 
Select and explain. 
A. Growth factor receptor, B. Cell cycle regulator, C. Signal transduction protein, D. Nuclear transcription factor
C: Signal transduction protein
Answer: C: Signal transduction protein 
Explanation: RAS is the most common oncogene mutation involved in human cancer.
It codes for signal transduction protein.
BRAF, ABL, JAK/STAT are other signal transduction proteins involved in neoplasia.