9025
In the present study, the clonal relationship was investigated between peripheral blood polymorphonuclear cells ( PMNCs ) and marrow progenitor cells and the origin of ringed sideroblasts in patients with refractory anemia with ring sideroblasts ( RARS ) by polymerase chain reaction ( PCR ) of HUMARA gene .
 peripheral blood polymorphonuclear cells, PMNCs, HUMARA gene, ring sideroblasts, ringed sideroblasts, RARS, marrow progenitor cells
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 peripheral blood polymorphonuclear cells, PMNCs, HUMARA gene, ring sideroblasts, ringed sideroblasts, RARS, marrow progenitor cells