3439
The embryology of the vertebral column is reviewed briefly , and the origin of each anomaly of the C2 vertebra is traced to one of the two early stages in development as follows : 1 ) the formation of the mesenchymal vertebra or 2 ) its induction to cartilage .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 None