Cancer is generally developed through accumulation of multiple genetic mutations. Epigenetic abnormalities of DNA methylation and histone modification patterns were also found in most cancer cells. Although induced pluripotent stem cells (iPSCs) can be generated through epigenetic reorganization without affecting the underlying genomic sequencing, they have some shared characteristics with cancer cells, which include unlimited growth potential. Taking advantages of such properties of iPSC derivation, the reprogramming technology is applicable not only for regenerative medicine but also for cancer research. Here, we introduce the potential application of iPSC technology for better understandings of cancer biology. Especially, we would like to propose the role of cellular identity in cancer development.