Abstract: The present invention provides a method of upregulating expression of a protein of interest (e.g., a native protein) in a cell, the cell containing a DNA encoding the protein, which DNA contains a mutation that causes downregulation of the protein by aberrant splicing in a pre-mRNA, wherein the DNA encodes the pre-mRNA; wherein the pre-mRNA contains a native intron having a first set of splice elements, which native intron is removed by splicing when the mutation is absent to produce a first mRNA encoding the protein; and wherein the pre-mRNA further contains an aberrant intron different from the native intron having a second set of splice elements, which aberrant intron is removed by splicing when the mutation is present to produce an aberrant second mRNA different from the first mRNA.