DPPA2 and amyotrophic lateral sclerosis: Furthermore, colonies from ALS and non-ALS subjects showed NANOG, SOX2, OCT4, DPPA4, ESG/DPPA, DPPA2, REX1, GDF3, and CHAT signals which were similar to those of an hESC line and substantially different from the iPSC-differentiated motor neurons (Figure 2A).