By the ectopic expression of Lhx2 in OP9 cells, for instance, Chen et al. coinjected PSCs and OP9-Lhx2 into immunodeficient mice, which increased the proportion of hematopoietic progenitors with a transient repopulation capability compared with that of OP9/PSCs via teratoma formation. This evidence concerns the gene LHX2 and teratoma.