1372
The various forms of sickle cell disease share the common feature of an abnormal globin chain that , under certain conditions such as hypoxia , results in the sickling of red blood cells and obstruction of blood vessels .
 globin chain
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 globin chain