Interestingly, tumor cells with low CD34 expression displayed greater tumorigenicity than cells with high CD34 expression in the Tgfbr2 cKO + Hras backskin SCC (Schober and Fuchs, 2011), whereas we observed a dramatic enrichment for tumorigenicity in CD34+ SCC cells from transition zone tumors. The gene discussed is TGFBR2; the disease is neoplasm.