CXCR3 and infection: 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.