Notably, 2 out of 2 tumor-free mice (100%) vaccinated with differentiated ES-D3 cells developed tumors 8 days after the second LLC challenge, whereas only 25% of mice (2 out of 8) in the parental undifferentiated ES-D3 + STO/GM-CSF vaccination group developed tumors following LLC cell re-inoculation (Fig. 3D). This evidence concerns the gene CSF2 and neoplasm.