This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2019, Subject name: Pathology
In alveolar variant of rhabdomyosarcoma , the resultant fusion protein is believed to function as 
Select and explain. 
A. Activated growth factor receptor, B. Chimeric transcription factor, C. Constitutively active kinase, D. Novel growth factor
B: Chimeric transcription factor
Answer: B: Chimeric transcription factor 
Explanation: In Alveolar rhabdomyosarcoma, there is frequently fusion of the FOXO1 gene to either the PAX3 or the PAX7 gene, rearrangements marked by the presence of (2;13) or(1;13) translocations, respectively. PAX3 is a transcription factor that initiates skeletal muscle differentiation, and it appears that the chimeric PAX3-FOXO1 fusion protein interferes with the gene expression program that drives differentiation.