8047
Also , since P . acnes living on the surface of skin receive the same radiation exposure as humans , we envision that the changes in porphyrin profiles ( the absorption spectra and / or metabolism ) of P . acnes by radiation may mirror the response of human cells to radiation .
 Chemical: porphyrin
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: porphyrin