highly significantP <10 −3
Unsupervised classification of E9.25 ysE, E12.5 ysE, cystic EBs and E12.5 fetal liver samples was done according to 3133 RefSeq protein coding genes that showed a highly significant ( P <10 −3 ) difference in expression between E12.5 fetal liver and E12.5 ysE ( Fig.