In addition, greater positivity of the Ki67 proliferative index as well as the p63 proliferative marker was found in lesions formed with HDFs with PDCD4 silencing, while expression of the involucrin and loricrin differentiation marker was less (Figure 6A, 6B and Supplementary Figure 2A), showing tumors formed with HDFs with PDCD4 silencing contain more undifferentiated tumor cells. The gene discussed is PDCD4; the disease is neoplasm.