DPPA3 and teratocarcinoma: In human, the chromosome region where NANOG is located also contains DPPA3, POU5F1P3 and another pluripotency factor, GDF3, and collectively is called a ‘hotspot for teratocarcinoma’ owing to the high rate of chromosomal abnormalities (Clark et al., 2004; de Jong et al., 1990; Murty et al., 1990; Pain et al., 2005).