A system for stable expression of gene pathways in cell lines, methods of making cell lines with stable expression of gene pathways, and methods of using the same are disclosed herein. The system comprises a nucleic acid construct configured to encode at least two genes of a multigene pathway in a cell. The nucleic acid construct comprises a plurality of nucleic acid sequences, wherein the plurality of nucleic acid sequences comprises: a first nucleic acid sequence encoding at least one gene of the multigene pathway; a first protease recognition nucleic acid sequence encoding a protease recognition site; a first linker nucleic acid sequence encoding a linker region, wherein the linker region comprises a viral 2A peptide; and a second nucleic acid sequence encoding at least one gene of the multigene pathway.