An objective of the present invention is to provide vectors for conveniently and efficiently producing ES-like cells in which foreign genes are not integrated into the chromosome. The present inventors discovered methods for producing ES-like cells from somatic cells using chromosomally non-integrating viral vectors. Since no foreign gene is integrated into the chromosome of the produced ES-like cells, they are advantageous in tests and research, and immunological rejection and ethical problems can be avoided in disease treatments.

An objective of the present invention is to provide vectors for conveniently and efficiently producing ES-like cells in which foreign genes are not integrated into the chromosome. The present inventors discovered methods for producing ES-like cells from somatic cells using chromosomally non-integrating viral vectors. Since no foreign gene is integrated into the chromosome of the produced ES-like cells, they are advantageous in tests and research, and immunological rejection and ethical problems can be avoided in disease treatments.