8540
Phylogenetic analysis of many representative vertebrate species ( including fish , amphibians , birds and mammals ) indicated the presence of ALDH1B1 in many mammalian species and in frogs ( Xenopus tropicalis ) ; no evidence was found for ALDH1B1 in the genomes of birds , reptiles or fish .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None