To validate the observed increased invasion potential of human melanoma cells after YY1 knockdown in an in vivo model, we generated a human melanoma cell line carrying a tracer (red fluorescent protein, RFP) and a doxycycline-inducible shRNA construct targeting YY1 to be used for grafting into immunocompromised mice (Figure 4I). The gene discussed is YY1; the disease is melanoma.