Analisis Histologi dan Ekspresi Gen Matrix Metalloproteinase-2 (MMP-2) Satu Minggu Pascainjeksi Umbilical Cord-Mesenchymal Stem Cell (UC-MSC) pada Fibrosis Hati Kelinci Oryctolagus cuniculus (Linnaeus, 1758) = Histological Analysis and Gene Expression of Matrix Metalloproteinase-2 (MMP-2) One Week Postinjection Umbilical Cord-Mesenchymal Stem Cell (UC-MSC) in Rabbit Oryctolagus Cuniculus (Linnaeus, 1758) Liver Fibrosis