Transcription factors are a type of proteins that regulate the synthesis of RNAs from genomic DNA (transcription). Transcriptional program is strictly regulated in a tissue- and stage-specific manner that requires a number of transcription factors to work in a cascade or in a loop. In other words, the disruption of transcriptional program alters cellular state and may predispose cells to the acquisition of genetic abnormalities, potentially giving rise to cancerous cell behavior. Interestingly, several transcription factors, which characterize cell identity and regulate developmental process (called “master transcription factors”), have been implicated as oncogenes in many cancers. Their oncogenic property can be attributed to their ability to govern the transcriptional program as a master regulator and to utilize the endogenous machinery unique to each cell type. In our laboratory, we aim to discover the roles of master transcription factors in tissue-specific oncogenesis.