The differences between our models may explain our distinct observations: 1) A431 is an HPV-negative carcinoma cell line; therefore, overexpression of K17 was not induced by papillomavirus infection, while the K17 overexpression is induced by MmuPV1 infection in our model; and 2) overexpression of CXCR3 ligands in our model is induced by an immune microenvironment induced by MmuPV1 infection, which may involve different signaling pathways than mediated by TPA. The gene discussed is CXCR3; the disease is carcinoma.