Further CF lung modifier genes, such as ETS homologous factor (EHF), (Epithelial splicing regulatory protein 2) ESRP2 and macrophage migration inhibitory factor (MIF) have functional roles in epithelial to mesenchymal transition, a process that is also epigenetically regulated and plays a major role in lung cancer development [61–65]. The gene discussed is ESRP2; the disease is lung cancer.