SPP1 and melanoma: The blockade of thrombin cleavage of OPN in the OPNR153A KI mouse relieves this suppression of the host anti-tumor immune response, allowing the increased infiltration of TAMs into the tumor but the fraction of M1 and M2 TAMs is reduced while the fraction of the new phenotype TAMs (CD11b+CD11c−CD206+Ly6G−) is increased, resulting in the suppression of B16 melanoma growth and metastasis in this model.