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: Surgery
Blast cells of ALL in childhood have: 
Select and explain. 
A. Excessive mitochondria, B. Antibodies on WBC, C. CALLA+ve, D. Surface antigen
C: CALLA+ve
Answer: C: CALLA+ve 
Explanation: CALLA +ve The blast cells of ALL mayor may not react to Common Acute Lymphocytic Leukemia Antigen (CALLA). They are classified as CALLA +ve or CALLA -ve