Previously, we found that the PLCG1 gene is located within the CDR of del(20q) observed in MDS.6 Haploinsufficiency because of del(20q) may reduce PLCG1 expression, but there were no significant differences in expression levels of PLCG1 between MDS patients with del(20q) and those without del(20q), which suggests that reduced PLCG1 expression is not specific in MDS patients with del(20q), but a common molecular event in MDS. The gene discussed is PLCG1; the disease is myelodysplastic syndrome.