Analysis of embryonic stem (ES) cells following depletion of the histone H3 Lys 9 demethylase genes, Jmjd1a and Jmjd2c. Pluripotent ES cells possess the ability to self-renew indefinitely. Results provide insight into the role of Jmjd1a and Jmjd2c in the maintenance of self-renewal in ES cells.