MKI67 and neoplasm: As shown in Figure 7C, we could not observe significant structural differences in tumor histological organization, with untreated or IL-22-treated tumors showing the presence of proliferating (Ki-67+, Keratin 14+ and Keratin 5+) and differentiating (Keratin 1+) keratinocytes in tumor outer or inner cell masses, respectively (data not shown), as previously reported [34].