1473
Using neuroblastoma - derived Neuro - 2a cells to investigate the function of ARIP1 , we found that overexpression of ARIP1 down - regulated the activin A - induced signal transduction and significantly decreased the voltage - gated Na ( + ) current ( I ( Na ) ) .
 Chemical: Na ( + ); Chemical: Na
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: Na ( + ); Chemical: Na