Do iPSCs retain characteristics of their somatic origin?

In "Molecular Control of Induced Pluripotency, Cell Stem Cell, 14:720, 2014"

The question of whether iPSCs retain characteristics of their somatic origin has been a subject of considerable interest. While low-passage iPSCs may exhibit some epigenetic memory (Kim, et al., 2010), extended passaging brought the methylation patterns of iPSCs closer to ESCs (Nishino et al., 2011).

PLoS Genet. 2011 May;7(5):e1002085. doi: 10.1371/journal.pgen.1002085. 

DNA methylation dynamics in human induced pluripotent stem cells over time.

Nishino K1, Toyoda M, Yamazaki-Inoue M, Fukawatase Y, Chikazawa E, Sakaguchi H, Akutsu H, Umezawa A.