The present invention relates to a method of modulating pluripotency and/or self-renewing characteristics of a stem/progenitor cell. The method comprises administering to the respective cell a compound of the general formula (I) In the general formula A is C or N. R 1 , R 4 and R 5 are, independently selected, H or aliphatic, cycloaliphatic, aromatic, arylaliphatic, or arylcycloaliphatic hydrocarbyl groups, that comprise 0 - 3 heteroatoms being N, O, S, or Si. R 4 and R 5 may optionally be linked so as to define an aliphatic hydrocarbyl bridge. R 2 is H or a halogen, such as F or Cl. R 3 is H, or an aliphatic or arylaliphatic hydrocarbyl group comprising 1 - 8 main chain carbon atoms and 0 - 3 heteroatoms being N, O, S, Si, or a halogen such as Cl or F. Also provided is a method for modulating gene expression in a cell that expresses the components of a polycomb repressive complex.