The relative quantification (RQ) of Mmp9 mRNA expression in neutrophils was 830.75-fold of inter-HF-keratinocytes (Sca-1+), 59.24-fold of HF-keratinocytes (Sca-1−), 106.96-fold of monocytes, 27.6-fold of macrophages, 18.38-fold of T cells, 7.06-fold of LCs and 23.2-fold of dermal DCs (dDCs) respectively. The gene discussed is MMP9; the disease is hydrops fetalis.