**1. Introduction**

We have learned that genes in mammalian cells are transcribed into messenger RNAs (mRNAs), which are to be translated into polypeptides (proteins). This is known as "Central Dogma." Gene expression must be appropriately maintained to regulate development, differentiation, and proliferation of cells. Imbalances or disturbances in gene expression are sometimes deleterious for living things. For example, steroid and thyroid hormones directly bind to nuclear receptors, which induce expression of specific genes. Recent global analyses of gene transcripts revealed that specific transcription factors (TFs) and their networking systems physiologically correspond to the onset of human diseases, including cancer. In other words, expression of specific genes might have relevance to pathogenesis of diseases. Given that OKSM (Yamanaka) factors convert somatic cells into induced pluripotent stem (iPS) cells, alterations in transcriptional state could affect destiny of the cells. In this chapter, revisiting known TFs, we would argue if transcription controlling strategies could contribute for the novel therapies on human diseases.
