3521
Here , we investigate SA - DNAm changes in mesenchymal stromal cells ( MSC ) upon long - term culture , irradiation - induced senescence , immortalization , and reprogramming into induced pluripotent stem cells ( iPSC ) using high - density HumanMethylation450 BeadChips .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities:  
Answer:
 None