sentences:  sought to identify the key region and factors related to the efforts of gene expression of the C4 gene.Their research concluded with the fact that the Sp1 binding site (positioned at -59 to -49) plays an important role in accurately starting basal transcription of C4.Utilization of electromobility shift assays and DNase I footprint analyses demonstrated specific DNA-protein correlations of the C4 promoter at the nuclear factor 1, two E box (-98 to -93 and -78 to -73), and Sp1 binding domains.