Although we cannot normalize their chromosomes and genes with chemical drugs, we may be able to manipulate the amounts and patterns of mRNAs transcribed from patients DNAs with small chemicals. Based on this simple idea, we have looked for chemical compounds which can be applicable for human diseases targeting kinase families of CDKs, CLKs and DYRKs which are involved in the regulation of gene expression, and eventually succeeded to find FIT039, TG003, and ALGERNON as potential therapeutic drugs to cure diseases such as viral infections, Duchenne muscular dystrophy, and Down syndrome, respectively. In addition, we established splicing reporter assay of pathogenic genes, and found splicing modulators which can rectify the aberrant mRNA splicing in patient cells of familial dysautonomia, cardiac Fabry diseas, and type V cystic fibrosis. With the original drug discovery methods, we have found potential drugs available for wide ranges of diseases, and some of them already entered into the stages of clinical trials.