Disclosed is a method which uses promoters, enhancers and the like to increase the expression of genes, in particular exogenous genes. Further disclosed is a cassette for increasing gene expression which includes promoters, enhancers and the like. The expression cassette contains a gene which is to be expressed and a DNA construct having a poly-A-addition sequence, which are downstream of a first promoter, and further contains a second promoter or an enhancer, downstream of the DNA construct.