IHC staining showed that human Ki67 (a proliferation marker) in tumor GTPCH-expressing fibroblast coimplants increased by 25% compared to the MDA231-GFP alone or the control coimplants (Figure 6B), noting that murine Ki67 contributed less than 5% to each tumor mass (Figure 6C). The gene discussed is MKI67; the disease is neoplasm.