Human gene expression is exquisitely regulated at several points of between transcription and protein synthesis to ensure fidelity in the conversion of genetic information into biological functions. Nonsense-mediated mRNA decay (NMD) is a post-transcriptional surveillance pathway responsible for the recognition and degradation of mRNAs containing premature termination codons. NMD protects cells from nonfunctional, potentially harmful, polypeptides encoded by mutated mRNAs. On the other hand, NMD degrade frameshift or miss-spliced mRNAs encoding cancer antigen. Hence, manipulation of NMD activity will benefit to improve anti-cancer immune response. We are challenging this fundamental post-transcriptional gene expression regulation pathway and developing novel drugs for cancer and rear genetic diseases. Using our original technique, which developed during basic analysis of NMD, we are analyzing disease related post-transcriptional event of gene expression mechanisms. The goal of the research is to find the critical factors of diseases and develop/perform the primary compound screening targeting these factors.