Overexpression of protein-of-interest can be effectively done by (i) cloning the Open Reading Frame (ORF), only the protein-coding sequences, into a vector with a strong promoter. This is ideal for protein purification. This also makes it easy to fuse the protein with additional protein tags like HA, and FLAG. (ii) cloning the cDNA, containing both 5’ and 3’ UTR of the gene in an expression plasmid under the regulation of a strong promoter. These plasmids are preferred to study the intrinsic gene regulatory mechanisms. The plasmids are then introduced into the cell using chemical transfection, lentiviral transduction, or electroporation based on the needs of the individual study and the characteristics of the cells. These cells are useful for protein expression and purification, studying gene functions, and protein localization studies.